Seed Germination Database

A seed is an embryo plant and contains within itself virtually all the materials and 

energy to start off a new plant. To get the most from one's seeds it is needful to 

understand a little about their needs, so that just the right conditions can be given 

for successful growth. 

One of the most usual causes of failures with seed is sowing too deeply; a seed has 

only enough food within itself for a limited period of growth and a tiny seed sown 

too deeply soon expends that energy and dies before it can reach the surface. 

Another common cause is watering. Seeds need a supply of moisture and air in the 

soil around them. Keeping the soil too wet drives out the air and the seed quickly 

rots, whereas insufficient water causes the tender seedling to dry out and die. 

Watering of containers of very small seeds should always be done from below, 

allowing the water to creep up until the surface glistens.

Most seeds will of course only germinate between certain temperatures. Too low 

and the seed takes up water but cannot germinate and therefore rots, too high and 

growth within the seed is prevented. Fortunately most seeds are tolerant of a wide 

range of temperatures but it is wise to try to maintain a steady, not fluctuating 

temperature, at around the figure we have recommended in our guide. Once several 

of the seeds start to germinate the temperatures can be reduced by about 5 degrees 

F and ventilation and light should be given.

Some perennials and tree and shrub seeds can be very slow and erratic in 

germination. This may sometimes be due to seed dormancy, a condition which 

prevents the seed from germinating even when it is perfectly healthy and all 

conditions for germination are at optimum. The natural method is to sow the 

seeds out of doors somewhere where they will be sheltered from extremes of 

climate, predators, etc. and leave them until they emerge, which may be two or 

three seasons later. Dormancy, however, can be broken artificially.

The Database

Only representative temperate zone species are listed in each of the cultivated genera. If your species is not listed, select a germination method to try from the same genus. If the genus is not listed, vegetative propagation may be preferred.  Names in green are common names.  Zone numbers refer to minimum hardiness for that species, if known. Special treatments are described on page 23. Please keep in mind: all tree seeds should be planted to a depth = to the width of the seed!

Abelia x grandiflora , Glossy abelia ,zone= 6, sow seed outdoors at time of collection, do not put seed into storage
Abeliophyllum distichum , White forsythia ,zone= 5, sow seed outdoors at time of collection, do not put seed into storage
Abies amabilis , Cascade Fir ,zone= 5, sow 4 wks @ 39ºF, move to 70ºF for germ.
Abies balsamea , Balsam Fir ,zone= 2, sow 4 wks @ 39ºF, move to 70ºF for germ.
Abies concolor , White Fir ,zone= 4 , sow 4 wks @ 39ºF, move to 70ºF for germ.
Abies fraseri , Fraser Balsam Fir ,zone= 4 , sow 4 wks @ 39ºF, move to 70ºF for germ.
Abies koreana , Korean Fir ,zone= 5 , sow 4 wks @ 39ºF, move to 70ºF for germ. in darkness
Abies nordmanniana , Nordman Fir ,zone= 4 , sow 4 wks @ 39ºF, move to 70ºF for germ. in darkness
Abies procera , Noble Fir ,zone= 5 , sow @ 70ºF, if no germ. after 30d, move to 39ºF for 4 wks, return to 70ºF for germ.
Abies veitchii , Veitch's Fir ,zone= 3 , sow 4 wks @ 39ºF, move to 70ºF for germ. in darkness
Acanthopanax sieboldianus , Fiveleaf aralia ,zone= 4 , sow 6m @ 70ºF, then 3m @ 39ºF, recycle
Acer buergerianum , Trident Maple ,zone= 6 , sow @ 39ºF for germ. in 6 to 8 weeks
Acer campestre , Field Maple ,zone= 4 , sow 4 wks @ 70ºF, move to 39ºF for germ. in 3 to 6 months
Acer capillipes , Red Snake Bark Maple ,zone=   see A. pensylvanicum
Acer carpinifolium , Hornbeam Maple ,zone= 5 , sow 4 wks @ 70ºF, move to 39ºF for germ. in 3 to 6 months

Acer circinatum, Vine Maple, zone=5 , sow 3m @39ºF, then move to70ºF for germ.
Acer cissifolium , ,zone= 6 , sow 4 wks @ 70ºF, move to 39ºF for germ. in 3 to 6 months
Acer crataegifolium , Hawthorn Maple ,zone= 7 , sow 3m @ 39ºF, then remove seed coats and move to 70ºF for germ.
Acer davidii , Fr.david's Maple ,zone= 5 , see A. pensylvanicum
Acer ginnala , Amur maple, zone= 2 , sow @ 39ºF for germ. in 3 to 4 months
Acer griseum , Paperbark Maple, zone= 5 , soak, then scarify, sow 3m @ 39ºF, move to 70ºF for germ. (less than 10% viable seeds)
Acer japonicum , Fullmoon maple, zone= 5 , sow 3m @ 39ºF, then remove seed coats and move to 70ºF for germ.
Acer macrophyllum, Oregon Maple, zone= 5, sow 3m @ 39ºF, move to 70ºF for germ.

Acer mandschuricum , Manchurian maple ,zone= 4 , see A. griseum
Acer negundo , Box Elder Maple ,zone= 2 , Scratch and soak, sow 3m @ 39ºF, move to 70ºF for germ.
Acer nikoense , Nikko Maple ,zone= 5 , see A. griseum
Acer palmatum , Japanese maple ,zone= 5 , Sow directly outdoors during winter for germ. the following spring. Or, sow 3m @39ºF, move to70ºF for germ.
Acer pensylvanicum , Striped Maple ,zone= 3 , remove seed coat, sow @ 39ºF for germ. in 4 to 12 weeks
Acer platanoides , Norway maple ,zone= 3 , sow fresh seed only @ 39ºF for germ. in 3m
Acer pseudoplatanus , Sycamore maple ,zone= 4 , see A. griseum
Acer rubrum , Red Maple ,zone= 3 , sow at once upon ripening, or soak, then sow 9w @ 39ºF, move to 70ºF for germ.
Acer rufinerve , Snake Bark Maple ,zone= 6 , see A. pensylvanicum
Acer saccharinum , Silver Maple ,zone= 3 , sow fresh seed at @ 70ºF
Acer saccharum , Sugar Maple ,zone= 3 , sow 3m @ 39ºF, move to 70ºF for germ.
Acer sieboldianum, Sode No Uchi Maple, zone= 4, sow 3m @39ºF, move to70ºF for germ.

Acer spicatum , Mountain Maple ,zone= 2 , sow 3m @ 39ºF, move to 70ºF for germ.
Acer tataricum , Tatarian Maple ,zone= 4 , sow @ 39ºF for germ. in 3 to 6 months
Acer tegmentosum , Manchustripe Maple ,zone= 5 , see A. pensylvanicum
Acer triflorum , Three Flowered Maple ,zone= 6 , see A. griseum
Acer truncatum , Shantung Maple ,zone= 6 , see A. griseum
Actinidia arguta , Tara vine ,zone= 4 , sow 3m @ 39ºF, move to 70ºF for germ.
Actinidia kolomikta , Tara vine ,zone= 4 , sow 3m @ 70ºF, then 3m @ 39ºF, move to 70ºF for germ.
Aesculus carnea x , Red Horse-chestnut ,zone= 4 , sow fresh seed only - outdoors
Aesculus chinensis , Chinese Horse Chestnut ,zone= 6 , sow 3m @ 39ºF, move to 70ºF for germ.
Aesculus glabra , Ohio Buckeye ,zone= 5 , sow 3m @ 39ºF, move to 70ºF for germ.
Aesculus hippocastanum , Horse Chestnut ,zone= 3 , sow 3m @ 39ºF, move to 70ºF for germ.
Aesculus parviflora , Bottlebrush buckeye ,zone= 4 , sow fresh seed only - outdoors
Aesculus pavia , Red buckeye ,zone= 5 , sow 3m @ 39ºF, move to 70ºF for germ.
Aesculus sylvatica , Painted buckeye ,zone= 5 , sow fresh seed only - outdoors
Aesculus turbinata , Japanese Horse-chestnut ,zone= 6 , sow 3m @ 39ºF, move to 70ºF for germ.
Ailanthus altissima , Tree of heaven ,zone= 4 , sow @ 70ºF in light, if no germ. in 4w, move to 39ºF for 8w, recycle
Akebia quinata , Fiveleaf akebia ,zone= 4 , sow 8w @ 39ºF, move to 70ºF for germ.
Albizia julibrissin , Silk-tree, or Mimosa ,zone= 6 , soak, puncture seed coat, soak again, sow @ 70ºF
Alnus cordata , Italian Alder ,zone= 6 , direct sow fresh seed outdoors
Alnus glutinosa , Alder ,zone= 3 , direct sow fresh seed outdoors
Alnus incana , White Alder ,zone= 2 , direct sow fresh seed outdoors
Alnus rugosa , Speckled Alder ,zone= 2 , direct sow fresh seed outdoors
Alnus serrulata , Hazel Alder ,zone= ?, direct sow fresh seed outdoors
Amelanchier alnifolia , Serviceberry ,zone= 2 , sow 3m @ 39ºF, move to 70ºF for germ.
Amelanchier arborea , Downy Serviceberry ,zone= 4 , sow 3m @ 39ºF, move to 70ºF for germ.
Amelanchier canadensis , Shadblow Serviceberry ,zone= 4 , sow 3m @ 39ºF, move to 70ºF for germ.
Amelanchier grandiflora , ,zone= 4 , wash seeds 3x daily 7d, sow 3m @ 39ºF, move to 70ºF for germ.
Amelanchier laevis , Allegheny serviceberry ,zone= 4 , sow 3m @ 70ºF, 3m @ 39ºF, 3m @ 70ºF, move to 39ºF for germ. in 10 to 12 wks
Amelanchier sanguinea , Utah Serviceberry ,zone= 3 , sow 3m @ 39ºF, 3m @ 70ºF, 3m @ 39ºF, move to 70ºF for germ. in 4 weeks
Amelanchier stolonifera , Running serviceberry ,zone= ?, sow fresh seed 3m @ 39ºF, move to 70ºF for germ. in 3 wks
Amorpha canescens , Leadplant ,zone= 2 , nick coat , sow @ 70ºF, if no germ., move to 39ºF for 4 wks, recycle
Amorpha fruticosa , Indigobush ,zone= 4 , nick coat , sow @ 70ºF, if no germ., move to 39ºF for 4 wks, recycle
Ampelopsis brevipedunculata , Porcelain ampelopsis ,zone= 4 , wash seeds 3x daily 7d, sow 3m @ 39ºF, move to 70ºF for germ.
Anisostichus capreolata , Crossvine ,zone= 6 , sow @ 70ºF
Aralia elata , Chinese Aralia ,zone= 4 , GA-3 soak, sow @ 70ºF for germ. in 3-9w
Aralia racemosa , American Spikenard ,zone= 4 , sow fresh seed outdoors in the fall
Aralia spinosa , Devils-walkingstick ,zone= 4 , sow 3m @ 39ºF, move to 70ºF for germ.
Arbutus menziesii , Madrone ,zone= 7 , sow 3m @ 39ºF, move to 70ºF for germ.
Arctostaphylos uva-ursi , Kinnikinick ,zone= 2 , scarify coat, sow 3m @ 70ºF, 3m @ 39ºF, move back to 70ºF for germ.
Aristolochia durior , Dutchman's pipe ,zone= 4 , direct sow outdoors in the fall
Aristolochia macrophylla , Pipevine ,zone= 6 , sow in light @ 70ºF for slow germ. 21-30d
Aronia melanocarpa , Black chokeberry ,zone= 4 , direct sow outdoors
Asimina triloba , Pawpaw ,zone= 5 , GA-3 soak, sow @ 70ºF for slow germ. 4-6w
Aucuba japonica , Japanese aucuba ,zone= 7 , sow @ 70ºF, slow to germ. slow to develop
Berberis candidula , Paleleaf barberry ,zone= 5 , wash seed 3x daily 7d, sow directly outdoors
Berberis julianae , Wintergreen Berberis ,zone= 5 , wash seed 3x daily 7d, sow directly outdoors
Berberis koreana , Korean barberry ,zone= 3 , sow 3m @ 39ºF, move to 70ºF for germ.
Berberis thunbergii , Japanese Berberis ,zone= 4 , sow directly outdoors
Betula albosinensis , Chinese Red Birch ,zone= 7 , sow 3m @ 39ºF, move to 70ºF for germ.
Betula alleghaniensis , Yellow Birch ,zone= 3 , see B. lenta
Betula davurica , Asian Black Birch ,zone= 3 , sow 3m @ 39ºF, move to 70ºF for germ.
Betula ermanii , Gold Birch ,zone= 3 , sow 3m @ 39ºF, move to 70ºF for germ.
Betula glandulosa , Bog birch ,zone= 1, sow 3m @ 39ºF, move to 70ºF in darkness
Betula grossa , Japanese Cherry Birch ,zone= 5 , sow 3m @ 39ºF, move to 70ºF for germ.
Betula lenta , Cherry Birch ,zone= 3 , sow 2m @ 39ºF, move to 90ºF daytime and 60ºF night oscillating temps. for germ.
Betula maximowicziana , Monarch Birch ,zone= 6 , sow 3m @ 39ºF, move to 70ºF for germ.
Betula nigra , Black Birch ,zone= 4 , direct sow outdoors only
Betula occidentalis (B. fontinalis) , Water birch ,zone= 4 , sow 3m @ 39ºF, move to 70ºF for germ.
Betula papyrifera , Paper Birch ,zone= 2 , direct sow outdoors in the fall
Betula pendula , Silver Birch ,zone= 2 , sow 3m @ 39ºF, move to 70ºF for germ.
Betula platyphylla , Asian white birch ,zone= 5 , sow 3m @ 39ºF, move to 70ºF for germ.
Betula populifolia , Grey Birch ,zone= 4 , sow 3m @ 39ºF, move to 70ºF for germ.
Betula pubescens , White Birch ,zone= 1 , sow @ 70ºF in light
Betula schmidtii , Schmidt birch ,zone= 5 , sow 3m @ 39ºF, move to 70ºF for germ.
Betula tianshanica , ,zone= ? , sow 3m @ 39ºF, move to 70ºF in light
Broussonetia papyrifera , Paper mulberry ,zone= 6 , sow @ 70ºF
Buddleia davidii , Butterfly-bush ,zone= 5 , sow @ 70ºF
Buxus microphylla , Boxwood ,zone= 6 , sow @ 70ºF, if no germ. in 4 wks, move to 39ºF for 4 to 12 wks, recycle
Buxus sempervirens , Boxwood ,zone= 5, sow @ 70ºF, if no germ. in 4 wks, move to 39ºF for 4 to 12 wks, recycle
Callicarpa dichotoma , Purple beautyberry ,zone= 5 , sow @ 70ºF
Callicarpa japonica , Japanese beautyberry ,zone= 5 , sow @ 70ºF
Calluna vulgaris , Scotch heather ,zone= 4 , sow @ 70ºF on peat moss
Calocedrus deccurens , California incensecedar ,zone= 5 , sow 2m @ 39ºF, move to 70ºF for germ.
Calycanthus floridus , Carolina allspice ,zone= 5 , sow fresh seed directly outdoors in the fall
Camellia japonica , Japanese camellia ,zone= 7 , remove seed from capsules, sow @ 70ºF
Campsis radicans , Trumpet vine ,zone= 4 , sow 2m @ 39ºF, move to 70ºF for germ.
Caragana arborescens , Siberian Pea Tree ,zone= 2 , soak, sow 3w @ 39ºF, move to 70ºF for germ.
Carpinus betulus , Hornbeam ,zone= 4 , collect seed while still green, and wings are just starting to turn yellow, sow 4 wks @ 70ºF, 3m @ 39ºF, move to 70ºF for germ.
Carpinus caroliniana , American Hornbeam ,zone= 2 , see C. betulus
Carpinus cordata , ,zone= 5 , see C. betulus
Carpinus coreana , Korean Hornbeam ,zone= 7 , see C. betulus
Carpinus japonica, ,zone= 4, sow 4 wks @ 70ºF, 3m @ 39ºF, move to 70ºF for germ.
Carpinus orientalis , Oriental Hornbeam ,zone= 5  , see C. betulus
Carpinus polyneura , ,zone= ?, see C. betulus
Carpinus schuschuensis x , ,zone= 6 , see C. betulus
Carpinus turczaninovii , ,zone= 7 , see C. betulus
Carpinus viminea , ,zone= 6 , see C. betulus
Carya cordiformis , Bitter-nut Hickory ,zone= 4 , soak 4d (change water often), sow 3-5m @ 39ºF, move to 70ºF for germ.
Carya glabra , Pig-nut Hickory ,zone= 4 , see C. cordiformis
Carya illinoiensis , Pecan ,zone= 5 , see C. cordiformis
Carya laciniosa , Shellbark Hickory ,zone= 5 , see C. cordiformis
Carya ovata , Shagbark Hickory ,zone= 4 , see C. cordiformis
Caryopteris incana , Bluebeard ,zone= 7 , sow fresh seed @ 70ºF for rapid germ. (seed stored more than 12 months is usually dead), will grow in zone 5, but hardiness is marginal depending upon depth of cold during winter.
Castanea mollissima , Chinese Chestnut ,zone= 4 , sow fresh seed 8-12w @ 39ºF, move to 70ºF for germ. (ephemeral seed must be stored moist if at all)
Catalpa speciosa , Western Catalpa ,zone= 5 , sow @ 70ºF
Ceanothus americanus , New Jersey tea ,zone= 4 , hot water soak, sow 3m @ 39ºF, move to 70ºF for germ.
Cedrela sinensis , Chinese cedrela ,zone= 5 , sow @ 70ºF
Cedrus atlantica , Atlas cedar ,zone= 6 , sow 2w @ 39ºF, move to 70ºF for germ.
Cedrus deodara , Deodar ,zone= 5 , sow 2w @ 39ºF, move to 70ºF for germ.
Cedrus libani , Cedar Of Lebanon ,zone= 6 , sow 2w @ 39ºF, move to 70ºF for germ.
Celastrus scandens , American bittersweet ,zone= 3 , store fresh seed 6m, then sow 3-6m @ 39ºF, move to 70ºF for germ.
Celtis occidentalis , Common hackberry ,zone= 2 , sow 3m @ 39ºF, move to 70ºF for germ.
Cephalanthus occidentalis , Buttonbush ,zone= 5 , sow @ 70ºF
Cephalotaxus fortunei , Chinese Plum Yew ,zone= 7 , sow 3m @ 39ºF, move to 70ºF for germ.
Cercidiphyllum japonicum , Katsura tree ,zone= 4 , sow @ 70ºF
Cercis canadensis , Eastern Redbud ,zone= 4 , scarify, sow 2m @ 39ºF, move to 70ºF for germ.
Cercis chinensis , Chinese Redbud ,zone= 6 , see C. canadensis
Cercocarpus ledifolius , Desert Mahogany ,zone= 6 , GA-3 soak (or try 5% hydrogen peroxide for 15 min.), sow 9m @ 39ºF, move to 70ºF for germ.
Chaenomeles speciosa , Flowering quince ,zone= 4 , sow 3m @ 39ºF, move to 70ºF for germ.
Chamaecyparis lawsoniana , Port Orford cedar ,zone= 5 , sow 3m @ 39ºF, move to 70ºF in light for germ.
Chamaecyparis nootkatensis , Golden Weeping Alaskan Cedar ,zone= 5 , sow 3m @ 39ºF, move to 70ºF in light for germ.
Chamaecyparis obtusa , Hinoki falsecypress ,zone= 4 . sow 3m @ 39ºF, move to 70ºF in light for germ.
Chamaecyparis thyoides , Atlantic white cedar ,zone= 3 , sow 3m @ 39ºF, move to 70ºF in light for germ.
Chimonanthus praecox , Fragrant wintersweet ,zone= 6 , collect seed in May or June when not fully dried, break the pericarp, then sow @ 70ºF
Chionanthus virginicus , White fringe tree ,zone= 3 , sow 3-5m @ 70ºF, then 1-2m @ 39ºF, move to 70ºF for germ.
Cladrastis lutea , Yellowwood ,zone= 4 , scarify, sow 3m @ 39ºF, move to 70ºF for germ.
Clematis x jackmanii , Jackman clematis ,zone= 3 , sow 3m @ 39ºF, move to 70ºF for germ.
Clethra alnifolia , Summersweet ,zone= 3 , sow fresh seed @ 70ºF
Cleyera japonica (Ternstroemia gymnanthera) , Japanese cleyera ,zone= 7 , direct sow outdoors in the fall
Colutea arborescens , Bladder-senna ,zone= 5 , scarify, sow @ 70ºF
Comptonia peregrina , Sweetfern ,zone= 2 , scarify, then GA-3 soak, sow @ 70ºF
Cornus alba , Tatarian dogwood ,zone= 2 , sow 3m @ 39ºF, move to 70ºF for germ.
Cornus alternifolia , Pagoda Dogwood ,zone= 3 , sow 2-5m @ 70ºF, 2-3m @ 39ºF, move to 70ºF for germ.
Cornus amomum , Silky dogwood ,zone= 5 , sow 4m @ 39ºF, move to 70ºF for germ.
Cornus canadensis , Bunchberry ,zone= 2 , scarify, sow 3m @ 70ºF, 3m @ 39ºF, move to 70ºF for germ.
Cornus florida , Flowering Dogwood ,zone= 5 , wash seeds, sow 5m @ 39ºF, move to 70ºF for germ.
Cornus kousa , Kousa Dogwood ,zone= 5 , sow 3m @ 39ºF, move to 70ºF for germ.
Cornus mas , Cornelian Cherry ,zone= 5 , wash seeds, sow 4m @ 70ºF, then 3m @ 39ºF, move to 70ºF for germ.
Cornus nuttallii , Mountain Dogwood ,zone= 7 , sow 3m @ 39ºF, move to 70ºF for germ.
Cornus officinalis (shan zhu yu) , Japanese Cornel ,zone= 6 , see C. mas
Cornus racemosa , Gray dogwood ,zone= 4 , scarify, sow 4m @ 39ºF, move to 70ºF for germ.
Cornus sanguinea , Common Dogwood ,zone= 5 , sow 3-5m @ 70ºF, 3m @ 39ºF, move to 70ºF for germ.
Cornus sericea (C. stolonifera) , Red osier dogwood ,zone= 2 , see C. alba
Corylopsis glabrescens , Fragrant winterhazel ,zone= 5 , sow 3-5m @ 70ºF, 3m @ 39ºF, move to 70ºF for germ. (difficult)
Corylopsis pauciflora , Buttercup Witch Hazel ,zone= 6 , see C. glabrescens
Corylopsis spicata , Spike Witch Hazel ,zone= 6 , see C. glabrescens
Corylus americana , American Filbert ,zone= 4 , see C. colurna
Corylus avellana , European Hazel ,zone= 4 , see C. colurna
Corylus colurna , Turkish Hazel ,zone= 5 , sow 3-5m @ 70ºF, 3m @ 39ºF, move to 70ºF for germ.
Corylus cornuta , Beaked Filbert ,zone= 4 , sow 3m @ 70ºF, then 3m @ 39ºF, recycle for germ. in the third period
Cotinus coggyria , Smokebush ,zone= 5 , scarify, sow 3m @ 39ºF, move to 70ºF for germ.
Cotoneaster apiculatus , Cranberry cotoneaster ,zone= 4 , scarify, sow 3m @ 39ºF, move to 70ºF for germ.
Cotoneaster dammeri , Bearberry cotoneaster ,zone= 5 , sow 3m @ 39ºF, then 3m @ 70ºF, recycle for some germination in each of 5 periods
Cotoneaster divaricatus , Spreading cotoneaster ,zone= 4 , see C. apiculatus
Cotoneaster horizontalis , Rockspray ,zone= 4 , see C. apiculatus
Cotoneaster lucidus , Hedge cotoneaster ,zone= 3 , see C. apiculatus
Cotoneaster multiflorus , Many-flowered cotoneaster ,zone= 3 , see C. apiculatus
Cotoneaster salicifolius , Willowleaf cotoneaster ,zone= 6 , see C. apiculatus
Crataegus crus-galli , Cockspur Thorn ,zone= 5 , scarify, sow 4m @ 70ºF, 5m @ 39ºF, move to 70ºF for germ.
Crataegus laevigata , Hawthorn ,zone= 5 , see C. crus-galli
Crataegus mollis , Red Haw ,zone= 5 , see C. crus-galli
Crataegus monogyna , Hawthorn ,zone= 5 , see C. crus-galli
Crataegus monogyna , Oneseed hawthorn ,zone= 5 , wash seeds 3x daily 7d, sow 3m @ 70ºF, then 3m @ 39ºF, recycle
Crataegus phaenopyrum , Washington Thorn ,zone= 5 , see C. crus-galli
Crataegus punctata , Thicket hawthorn ,zone= 4 , see C. crus-galli
Crataegus succulenta , fleshy hawthorn ,zone= 4 , see C. crus-galli
Cryptomeria japonica , Japanese cedar ,zone= 5 , soak cold, store 8w moist cold, then sow 3m @ 70ºF, 3m @ 39ºF, move to 70ºF for germ.
Cupressus lusitanica , Cedar of Goa ,zone= 8 , sow 3m @ 39ºF, move to 70ºF for germ.
Cyrilla racemiflora , Leatherwood ,zone= 5 , sow @ 70ºF
Cytisus scoparius , Scotch broom ,zone= 5 , hot water soak, sow @ 68ºF night and 86ºF daytime temps.
Daphne cneorum , Rose daphne ,zone= 4 , sow 3m @ 39ºF, move to 70ºF for germ.
Davidia involucrata , Handkerchief Tree ,zone= 6 , sow in damp paper towel at 70ºF until seed coats start to open, move to 39ºF for 3 months, then sow outdoors. Alt = sow outdoors, wait two successive spring seasons.
Diospyros virginiana , Persimmon ,zone= 4 , sow 3m @ 39ºF, move to 70ºF for germ.
Dirca palustris , Leatherwood ,zone= 4 , sow 3m @ 39ºF, move to 70ºF for germ.
Elaeagnus angustifolia , Russian olive ,zone= 2 , sow 3m @ 39ºF, move to 70ºF for germ.
Enkianthus campanulatus , Redvein enkianthus ,zone= 4 , sow @ 70ºF
Eriobotrya japonica , Loquat ,zone= 8 , sow @ 70ºF
Eucommia ulmoides , Chinese Rubber Tree ,zone= 5 , sow 4wks @ 39ºF, move to 70ºF for germ.
Euonymus alatus db , Winged Spindle Tree ,zone= 3 , wash seeds 3x daily 7d, direct sow outdoors
Euonymus atropurpureus , Wahoo ,zone= 4 , wash fresh seed 3x daily 7d in detergent, sow 3m @ 70ºF, then 3m @ 39ºF, recycle for some germination in each of the next 5 periods.
Euonymus bungeanus , winterberry ,zone= 4 , wash seed 3x daily 7d, sow @ 39ºF for germ. in about 5 wks.
Euonymus europaeus , Spindle Tree ,zone= 3 , sow 3m @ 70ºF, 2 to 4 months @ 39ºF, move to 70ºF for germ.
Euonymus fortunei , Wintercreeper ,zone= 4 , remove arils, sow 3m @ 39ºF, move to 70ºF for germ.
Euscaphis japonica, Korean Sweetheart tree, zone= 6, sow @ 70ºF, 1 to 4 months for germ.

Evodia daniellii , Korean evodia ,zone= 4 , direct sow outdoors
Exochorda racemosa , Pearlbush ,zone= 4 , sow 2m @ 39ºF in damp paper towels, the direct sow outdoors
Fagus grandifolia , American Beech ,zone= 3 , sow 3m @ 39ºF, move to 70ºF for germ.
Fagus sylvatica , European Beech ,zone= 4 , direct sow outdoors in the fall
Forsythia x intermedia , Border forsythia ,zone= 4 , sow 4wks @ 39ºF, move to 70ºF for germ.
Fothergilla gardenii , Dwarf fothergilla ,zone= 5 , sow 6m @ 70ºF night and 86ºF daytime temps, then 3m @ 39ºF, move to 70ºF for germ.
Fothergilla major , Large fothergilla ,zone= 4 , sow 12m @ 70ºF night and 86ºF daytime temps, then 3m @ 39ºF, move to 70ºF for germ.
Franklinia alatamaha , Franklinia ,zone= 5 , collect fresh seed before it has dried, sow @ 70ºF
Fraxinus americana , White Ash ,zone= 3 , sow 4 wks @ 70ºF, then 2m @ 39ºF, move to 70ºF for germ.
Fraxinus anomala , Single Leaf Ash ,zone= 6 , sow 3m @ 39ºF, move to 70ºF in darkness
Fraxinus excelsior , European Ash ,zone= 4 , see F. pennsylvanica
Fraxinus mandshurica , Manchurian Ash ,zone= 6 , sow 6m @ 70ºF, then 6m @ 39ºF, recycle
Fraxinus ornus , Flowering Ash ,zone= 6 , see F. pennsylvanica
Fraxinus pennsylvanica , Green Ash ,zone= 4 , sow 2m @ 70ºF, then 4m @ 39ºF, move to 70ºF for germ.
Fraxinus quadrangulata , Blue Ash ,zone= 4 , see F. pennsylvanica
Gaylussacia brachycera , Box huckleberry ,zone= 5 , sow 4wks @ 70ºF night and 86ºF daytime temps, then 30-50d @ 50ºF for germ.
Gelsemium sempervirens , Carolina yellow jessamine ,zone= 6 , sow @ 70ºF
Genista tinctoria , Woadwaxen ,zone= 4 , scarify and soak, sow @ 70ºF
Ginkgo biloba , Maidenhair tree ,zone= 3 , wash seed, sow 10w @ 70ºF in moist sand, then 3m @ 39ºF, move to 70ºF for germ.
Gleditsia triacanthos , Honey Locust ,zone= 3 , puncture seed coat, sow @ 70ºF
Gleditsia triacanthos v inermis , Thornless Honey Locust ,zone= 3 , scarify, sow @ 70ºF
Gymnocladus dioica , Kentucky Coffee Tree ,zone= 4 , scarify, sow @ 70ºF
Halesia carolina , Carolina silverbell ,zone= 5 , sow 3m @ 70ºF, then 3m @ 39ºF, recycle for germ. in 4th period
Halesia monticola , Mountain Silverbell ,zone= 5 , see H. carolina
Hamamelis japonica , Japanese Witch Hazel ,zone= 5 , sow 2m @ 70ºF, then 3m @ 39ºF, recycle
Hamamelis mollis , Chinese Witch Hazel ,zone= 6 , sow 3m @ 70ºF, then 3m @ 39ºF, recycle
Hamamelis vernalis , Vernal witchhazel ,zone= 4 , sow 2m @ 70ºF, then 3m @ 39ºF, recycle
Hamamelis virginiana , Virginian Witch Hazel ,zone= 5 , sow 2m @ 70ºF, then 3m @ 39ºF, recycle
Hamamelis x intermedia , ,zone= 5 , sow 2m @ 70ºF, then 3m @ 39ºF, recycle
Hedera helix , English ivy ,zone= 4 , wash seed, sow 3m @ 39ºF, move to 70ºF for germ.
Hibiscus syriacus , Rose-of-Sharon ,zone= 5 , sow @ 70ºF, or direct sow outdoors
Hippophae rhamnoides , Seabuckthorn ,zone= 3 , sow 3m @ 39ºF, move to 70ºF for germ.
Hovenia dulcis , Japanese raisintree ,zone= 5 , scarify, sow @ 70ºF
Hydrangea anomala subsp. petiolaris , Climbing hydrangea ,zone= 4 , sow 1m @ 39ºF, move to 70ºF for germ.
Hydrangea quercifolia , Oakleaf hydrangea ,zone= 5 , sow fresh seed only, @ 70ºF
Hypericum prolificum , Shrubby St. Johnswort ,zone= 3 , sow @ 70ºF
Iberis sempervirens , Candytuft ,zone= 4 , sow @ 70ºF
Ilex aquifolium , English Holly ,zone= 6 , see I. cornuta
Ilex cornuta , Chinese holly ,zone= 7 , wash seed 3x daily 14d, then sow @ 72ºF for slow germ. up to 18 months in bagged pots
Ilex crenata , Japanese Holly ,zone= 6 , see I. cornuta, except shorter time to germ.
Ilex opaca , American Holly ,zone= 5 , see I. cornuta
Ilex vomitoria , Yaupon ,zone= 7 , see I. cornuta, except shorter time to germ.
Illicium floridanum , Florida anise-tree ,zone= 8 , sow @ 70ºF
Itea virginica , Sweetspire ,zone= 5 , sow @ 70ºF
Juglans cinerea , Butternut ,zone= 4 , direct sow outdoors in the fall
Juglans nigra , Black Walnut ,zone= 4, direct sow outdoors in the fall
Juglans regia , English Walnut ,zone= 5 , direct sow outdoors in the fall
Juniperus chinensis , Chinese Juniper ,zone= 4 , gather ripe berries, wash seed 3x daily 7d, scarify, then sow 4m @ 39ºF, move to 70ºF for germ.
Juniperus communis , Juniper ,zone= 7 , see J. chinensis
Juniperus conferta , Shore juniper ,zone= 6 , see J. chinensis
Juniperus horizontalis , Creeping Juniper ,zone= 4 , see J. chinensis
Juniperus sabina , Savin juniper ,zone= 3 , see J. chinensis
Juniperus virginiana , Eastern Red Cedar ,zone= 4 , see J. chinensis
Kalmia angustifolia , Sheep Laurel ,zone= 2 , sow @ 70ºF on peat moss in light
Kalmia latifolia , Mountain-laurel ,zone= 4 , sow @ 70ºF on peat moss in light
Kalopanax pictus , Castor-aralia ,zone= 4 , scarify, sow 3m @ 70ºF, then 3m @ 39ºF, move to 70ºF for germ.
Koelreuteria paniculata , Golden Rain tree ,zone= 5 , scarify, sow 3m @ 39ºF, move to 70ºF for germ.
Koelreuteria bipinatta , Chinese Flame tree ,zone= 5 , scarify, sow 3m @ 39ºF, move to 70ºF for germ.

Kolkwitzia amabilis , Beautybush ,zone= 4 , sow @ 70ºF
Laburnum x watereri , Goldenchain tree ,zone= 5 , scarify, sow @ 70ºF
Lagerstroemia indica , Crapemyrtle ,zone= 7 , sow 2m @ 39ºF, move to 70ºF for germ.
Larix decidua , European Larch ,zone= 4 , sow 2m @ 39ºF, move to 70ºF for germ.
Larix gmelinii , Dahurian Larch ,zone= 1 , sow 2m @ 39ºF, move to 70ºF for germ.
Larix kaempferi , Japanese Larch ,zone= 4 , sow 2m @ 39ºF, move to 70ºF for germ.
Larix laricina , American Larch ,zone= 2 , sow 2m @ 39ºF, move to 70ºF for germ.
Larix occidentalis , Western Larch ,zone= 4 , sow 2m @ 39ºF, move to 70ºF for germ.
Larix russica , Siberian Larch ,zone= 1 , sow 2m @ 39ºF, move to 70ºF for germ.
Ledum groenlandicum , Labrador tea ,zone= 2 , sow @ 70ºF on peat moss
Leiophyllum buxifolium , Box sandmyrtle ,zone= 5 , sow @ 70ºF on peat moss
Lespedeza bicolor , Shrub bushclover ,zone= 4 , direct sow outdoors
Leucothoe fontanesiana , Fetterbush ,zone= 4 , sow @ 70ºF on peat moss
Ligustrum amurense , Amur privet ,zone= 3 , wash seed 3x daily 7d, direct sow outdoors
Ligustrum japonicum , Japanese privet ,zone= 7 , wash seed 3x daily 7d, direct sow outdoors
Ligustrum obtusifolium , Border privet ,zone= 3 , wash 3x daily 7d, store seed 6m, then sow @ 70ºF for germ. in 13 wks
Ligustrum sinense , Chinese privet ,zone= 7 , wash seed 3x daily 7d, direct sow outdoors
Lindera benzoin , Spice Bush ,zone= 5 , sow 4wks @ 77ºF, then 3m @ 39ºF, move to 70ºF for germ.
Lindera obtusiloba , Japanese spicebush ,zone= 6 , see L. benzoin
Liquidambar formosana , Formosan Gum ,zone= 7 , sow 1 to 3m @ 39ºF, move to 70ºF for germ.
Liquidambar styraciflua , Liquidambar ,zone= 5 , sow 1 to 3m @ 39ºF, move to 70ºF for germ.
Liriodendron tulipifera , Tulip Tree ,zone= 4 , sow 2 to 3m @ 39ºF, move to 70ºF for germ.
Liriope spicata , Lilyturf ,zone= 4 , wash seed 3x daily 7d, direct sow outdoors
Lonicera alpigena , Alps honeysuckle ,zone= 6 , sow 2m @ 39ºF, then 2m @ 70ºF, recycle until germ. occurs
Maackia amurensis , Amur maackia ,zone= 3 , hot water soak o/n, sow @ 70ºF
Maackia chinensis , Chinese maackia ,zone= 5 , hot water soak o/n, sow @ 70ºF
Maclura pomifera , Osage Orange ,zone= 5 , soak, sow 4 wks @ 39ºF, move to 70ºF for germ.
Magnolia acuminata and other species , Cucumber tree ,zone= 3 , remove seed coat, sow 3m @ 39ºF, then direct sow outdoors
Mahonia aquifolium , Oregon grapeholly ,zone= 4 , sow fresh seed 3m @ 39ºF, move to 70ºF for germ. (do not dry store seeds)
Malus hupehensis , Tea crabapple ,zone= 5 , sow 2m @ 39ºF, move to 70ºF for germ.
Melia azedarach , Chinaberry ,zone= 7 , sow @ 70ºF
Metasequoia glyptostroboides , Dawn Redwood ,zone= 5 , sow @ 70ºF
Mitchella repens , Partridgeberry ,zone= 3 , sow 2m @ 39ºF, move to 70ºF for germ.
Morus alba , White Mulberry ,zone= 4 , sow 2m @ 39ºF, move to 70ºF for germ.
Morus rubra , Red Mulberry ,zone= 5 , sow 2m @ 39ºF, move to 70ºF for germ.
Myrica pensylvanica , Northern bayberry ,zone= 2 , remove wax from seeds collected in October, sow 3m @ 39ºF, move to 70ºF for germ.
Nandina domestica , Nandina ,zone= 6 , direct sow outdoors for germ. in 2 years
Nemopanthus mucronatus , Mountain Holly ,zone= 5 , sow 3m @ 70ºF, then 3m @ 39ºF, recycle for germ. in 3 years
Nerium oleander , Oleander ,zone= 8 , sow @ 70ºF
Nothofagus dombeyi , Coigue ,zone= 8, GA-3 soak, sow 1w @ 39ºF, move to 70ºF for germ.
Nothofagus obliqua , Roble Beech ,zone= 8 , GA-3 soak, sow 3m @ 39ºF, move to 70ºF for germ.
Nothofagus procera , Rauli Beech ,zone= 7 , see N. dombeyi
Nothofagus pumilio , Lenga ,zone= 7 , see N. dombeyi
Nothofagus solanderi v cliffortoides , Mountain Beech ,zone= 8 , GA-3 soak, sow 3m @ 39ºF, move to 70ºF for germ.
Nyssa sinensis , Chinese Tupelo ,zone= 7 , direct sow outdoors
Nyssa sylvatica , Black Gum ,zone= 3 , sow 2m @ 39ºF, move to 70ºF for germ.
Ostrya virginiana , Ironwood ,zone= 4 , sow 6m @ 70ºF, then 6m @ 39ºF, recycle until germ. occurs
Oxydendrum arboreum , Sourwood ,zone= 5 , sow @ 70ºF on peat moss
Parrotia persica , Persian parrotia ,zone= 5 , sow 5m @ 68ºF night and 86ºF daytime temps, then 3m @ 39ºF, move to 70ºF for germ.
Parrotiopsis jacquemontia , ,zone= 5 , sow 6m @ 70ºF, then 6m @ 39ºF, recycle until germ. occurs
Parthenocissus quinquefolia , Virginia creeper ,zone= 3 , sow 4 wks @ 39ºF, move to 70ºF for germ. (invasive)
Paulownia tomentosa , Princess Tree ,zone= 5 , sow @ 68ºF night and 86ºF daytime temps. in light for germ. in 2 to 3 wks.
Phellodendron amurense , Amur Cork Tree ,zone= 3 , sow @ 70ºF
Philadelphus coronarius , Mock Orange ,zone= 4 , direct sow outdoors
Photinia villosa , Oriental photinia ,zone= 4 , sow 2m @ 39ºF, move to 70ºF for germ.
Physocarpus opulifolius , Ninebark ,zone= 2, sow 3m @ 39ºF, move to 70ºF for germ.
Physocarpus opulifolius , Eastern ninebark ,zone= 2 , sow @ 70ºF
Picea abies , Norway spruce ,zone= 2 , direct sow outdoors
Picea brewerana , Brewer's Weeping Spruce ,zone= 6 , direct sow outdoors
Picea engelmannii , Engelmann spruce ,zone= 2 , direct sow outdoors
Picea glauca , White Spruce ,zone= 2 , direct sow outdoors
Picea mariana , Black Spruce ,zone= 2 , direct sow outdoors
Picea omorika , Serbian Spruce ,zone= 5, direct sow outdoors
Picea orientalis , Oriental Spruce ,zone= 5, direct sow outdoors
Picea pungens , Colorado Spruce ,zone= 5 , direct sow outdoors
Picea pungens , Blue Colorado Spruce ,zone= 5 , sow 3m @ 39ºF, move to 70ºF for low germ.
Picea rubens , Red Spruce ,zone= 3 , direct sow outdoors
Pieris japonica , Japanese pieris ,zone= 5 , sow @ 70ºF on peat moss
Pinus aristata , Bristle Cone Pine ,zone= 3 , sow @ 70ºF
Pinus banksiana , Jack Pine ,zone= 2 , sow 2w @ 39ºF, move to 70ºF for germ.
Pinus cembra , Swiss Stone Pine ,zone= 1 , direct sow outdoors, or sow 9m @ 39ºF, move to 70ºF for germ.
Pinus densiflora , Japanese Red Pine ,zone= 5 , sow @ 70ºF
Pinus echinata , Shortleaf pine ,zone= 6 , sow @ 70ºF
Pinus flexilis , Limber Pine ,zone= 3 , sow 2m @ 39ºF, move to 70ºF for germ,
Pinus koraiensis , Korean Pine ,zone= 3 , sow @ 70ºF
Pinus mugo , Swiss Mountain Pine ,zone= 3 , sow @ 70ºF
Pinus nigra ssp nigra , Austrian Pine ,zone= 5 , sow @ 70ºF
Pinus parviflora , Japanese White Pine ,zone= 5, sow 3m @ 39ºF, move to 70ºF for germ.
Pinus peuce , Macedonian Pine ,zone= 5 , sow 2m @ 39ºF, move to 70ºF for germ.
Pinus ponderosa , Ponderosa Pine ,zone= 4 , sow @ 70ºF
Pinus resinosa , Red Pine ,zone= 3 , sow @ 70ºF
Pinus rigida , Pitch Pine ,zone= 4 , sow @ 70ºF
Pinus sabiniana , Digger Pine ,zone= 8 , sow 2m @ 39ºF, move to 70ºF for germ.
Pinus strobus , Eastern White Pine ,zone= 3 , sow 2m @ 39ºF, move to 70ºF for germ.
Pinus sylvestris , Scots Pine ,zone= 2 , sow @ 70ºF
Pinus taeda , Loblolly Pine ,zone= 7 , sow @ 70ºF
Pinus thunbergii (thunbergiana) , Japanese Black Pine ,zone= 6 , sow @ 70ºF
Pistacia chinensis , Chinese pistache ,zone= 6 , Collect bluish color fruits only, wash seed 3x daily 7d, sow @ 39ºF in damp paper towels, check for radicle emergence in approx. in 50-60d, then sow outdoors.
Platanus occidentalis , American Plane ,zone= 4 , sow 2m @ 39ºF, move to 70ºF for germ.
Platanus orientalis , Oriental Plane ,zone= 7 , sow 2m @ 39ºF, move to 70ºF for germ.
Platanus x acerifolia , London planetree ,zone= 4 , sow 2m @ 39ºF, move to 70ºF for germ.
Poncirus trifoliata , Hardy-orange ,zone= 6 , sow 3m @ 39ºF, move to 70ºF for germ.
Populus alba , White Poplar ,zone= 3 , sow @ 70ºF, if you must
Populus tremuloides , American Aspen ,zone= 1 , sow @ 70ºF
Potentilla fruticosa , Bush cinquefoil ,zone= 2 , sow @ 70ºF
Prinsepia sinensis , Cherry prinsepia ,zone= 3 , sow 3m @ 39ºF, move to 70ºF for germ.
Prunus avium , Sweet Cherry ,zone= 3 , wash fresh seed 3x daily 7d, sow 3m @ 70ºF, then 3m @ 39ºF, recycle for germ. in 3rd and 5th periods, i.e., 70,39,(70), 39, (70)
Prunus caroliniana , Carolina cherrylaurel ,zone= 7 , direct sow outdoors in the fall
Prunus cerasifera , Cherry plum ,zone= 4 , wash seed 3x daily 7d, direct sow outdoors in the fall
Prunus laurocerasus , English laurel ,zone= 6 , sow 3m @ 39ºF, move to 70ºF for germ.
Pseudocydonia sinensis , Chinese quince ,zone= 5 , sow 3m @ 39ºF, move to 70ºF for germ.
Pseudolarix x kaempferi , Golden-larch ,zone= 4 , sow 2m @ 39ºF, move to 70ºF for germ., low fertility
Pseudotsuga menziesii , Douglas Fir ,zone= 7 , sow @ 70ºF
Ptelea trifoliata , Hoptree ,zone= 3 , sow 3m @ 39ºF, move to 70ºF for germ.
Pterocarya fraxinifolia , Caucasian Wingnut ,zone= 5 , sow fresh seed @ 70ºF, direct sow dry seed outdoors
Pterostyrax hispida , Fragrant Epaulette Tree ,zone= 6 , sow 3m @ 39ºF, move to 70ºF for germ.
Punica granatum , Pomegranate ,zone= 7 , sow @ 70ºF
Pyracantha coccinea bs , Scarlet firethorn ,zone= 6 , sow 3m @ 39ºF, move to 70ºF for germ.
Pyrus calleryana 'bradford' , Bradford callery pear ,zone= 4 , sow 3m @ 33ºF, move to 70ºF for germ.
Quercus acutissima , Sawtooth oak ,zone= 5 , direct sow outdoors in the fall
Quercus alba , White Oak ,zone= 4 , direct sow outdoors in the fall
Quercus coccinea , Scarlet Oak ,zone= 4 , sow 3m @ 39ºF, move to 70ºF for germ.
Quercus imbricaria , Shingle oak ,zone= 4 , direct sow outdoors in the fall
Quercus macrocarpa , Bur Oak ,zone= 3 , direct sow outdoors in the fall
Quercus palustris , Pin oak ,zone= 4 , direct sow outdoors in the fall
Quercus phellos , Willow Oak ,zone= 6 , sow 3m @ 70ºF, then 3m @ 39ºF, recycle
Quercus robur , English Oak ,zone= 6 , sow @ 70ºF
Quercus rubra , Red Oak ,zone= 3 , sow 6w @ 39ºF, move to 70ºF for germ.
Quercus virginiana , Live Oak ,zone= 7 , direct sow outdoors in the fall
Raphiolepis umbellata , Indian hawthorn ,zone= 7 , wash seed 3x daily 7d, direct sow outdoors
Rhamnus cathartica , Common buckthorn ,zone= 2 , sow 3m @ 39ºF, move to 70ºF for germ.
Rhamnus frangula , Alder Buckthorn ,zone= 3 , sow 2m @ 39ºF, move to 70ºF for germ.
Rhododendron carolinianum , Carolina rhododendron ,zone= 5 , sow @ 70ºF on peat moss
Rhododendron catawbiense , Catawba rhododendron ,zone= 4 , sow @ 70ºF on peat moss
Rhododendron mucronulatum , Korean rhododendron ,zone= 4 , sow @ 70ºF on peat moss
Rhododendron schlippenbachii , Royal azalea ,zone= 4 , sow @ 70ºF on peat moss
Rhodotypos scandens , White Kerria ,zone= 5 , scarify, sow 2m @ 39ºF, move to 70ºF for germ.
Rhus typhina , Staghorn Sumach ,zone= 3 , scarify, sow @ 70ºF
Ribes alpinum , Alpine currant ,zone= 2 , direct sow outdoors
Robinia pseudoacacia , Black Locust ,zone= 3 , scarify, hot water soak, sow @ 70ºF
Rosa multiflora , Japanese rose ,zone= 5 , sow 4m @ 39ºF, move to 70ºF for germ.
Rosa rugosa , Saltspray rose ,zone= 2 , sow 4m @ 39ºF, move to 70ºF for germ.
Salix alba , White Willow ,zone= 2 , sow fresh seed @ 70ºF
Sambucus canadensis , American elder ,zone= 3 , sow 2m @ 68ºF, then 4m @ 39ºF in moist sand
Santolina chamaecyparissus , Lavender cotton ,zone= 6 , sow @ 70ºF
Sapindus drummondii , Western soapberry ,zone= 6 , wash seed 3x daily 7d, sow 50-60d @ 39ºF in damp paper towels until radicles emerge, then sow outdoors
Sassafras albidum , Sassafras ,zone= 4 , sow 4m @ 39ºF, move to 70ºF for germ.
Sciadopytis verticillata , Japanese Umbrella Pine ,zone= 6 ,sow 3m @ 65ºF in moist sand, then 3m @ 39ºF on peat moss
Sequoia sempervirens , Californian Redwood ,zone= 8 , direct sow outdoors in half shade after last frost in the spring.
Sequoiadendron giganteum , Giant Sequoia ,zone= 7 , sow @ 70ºF in darkness
Shepherdia canadensis , Russet buffaloberry ,zone= 2 , scarify, sow 3m @ 39ºF, move to 70ºF for germ.
Skimmia japonica , Japanese skimmia ,zone= 7 , wash seed 3x daily 7d, sow @ 70ºF
Sophora japonica , Japanese Pagoda Tree ,zone= 5 , scarify, sow @ 70ºF
Sorbaria sorbifolia , Ural false spirea ,zone= 2 , sow fresh seed @ 70ºF
Sorbus alnifolia , Korean Mountain Ash ,zone= 6 , sow 3m @ 39ºF, move to 70ºF for germ.
Sorbus americana , American Mountain Ash ,zone= 2 , sow 3m @ 39ºF, move to 70ºF for germ.
Sorbus aria , Whitebeam ,zone= 5 , sow 3m @ 39ºF, move to 70ºF for germ.
Sorbus aucuparia , Mountain Ash ,zone= 2 , sow 3m @ 39ºF, move to 70ºF for germ.
Sorbus cashmeriana , ,zone= 5 , sow 3m @ 39ºF, move to 70ºF for germ.
Spiraea x vanhouttei , Vanhoutte spirea ,zone= 3 , direct sow outdoors
Staphylea trifolia , Bladdernut ,zone= 5 , sow fresh seed only 3m @ 70ºF, then 3m @ 39ºF, move to 70ºF for germ.
Stephanandra incisa , Cutleaf stephanandra ,zone= 3 , sow fresh seed only 3m @ 70ºF, then 3m @ 39ºF, move to 70ºF for germ.
Stewartia ovata v grandiflora , Mountain Camellia ,zone= 5 , direct sow outdoors in the fall for germ. in the second following spring.
Stewartia pseudocamellia , Japanese Stewartia ,zone= 5 , direct sow outdoors for germ. in about 17m
Styrax japonicum , Japanese Snowbell ,zone= 5 , direct sow outdoors in the fall for germ. in the second following spring. Can be done faster (see Hard Seeds p23)
Styrax obassia , Fragrant Snowbell Tree ,zone= 6 ,  direct sow outdoors in the fall for germ. in the second following spring. Can be done faster (see Hard Seeds p23)
Symphoricarpos albus , Snowberry ,zone= 3 , scarify, sow 3m @ 70ºF, then 3m @ 39ºF, move to 70ºF for germ. Seed will not tolerate dry storage.
Symplocos paniculata , Sapphireberry ,zone= 4 , sow 3m @ 70ºF, then 3m @ 39ºF, move to 70ºF for germ.
Syringa reticulata , Japanese Tree Lilac ,zone= 5 , direct sow outdoors
Tamarix ramosissima , Five-stamen tamarix ,zone= 3 , sow @ 70ºF
Taxodium ascendens , Pond Cypress ,zone= 5 , soak 5 min. in ethyl alcohol, sow 3m @ 39ºF, move to 70ºF for germ.
Taxodium distichum , Bald cypress ,zone= 4 , soak 5 min. in ethyl alcohol, sow 3m @ 39ºF, move to 70ºF for germ.
Taxus cuspidata , Japanese Yew ,zone= 6 , direct sow outdoors
Thuja occidentalis , White Cedar ,zone= 2 , sow 2m @ 39ºF, move to 70ºF for germ.
Thuja orientalis , Oriental arborvitae ,zone= 5 , sow 2m @ 39ºF, move to 70ºF for germ.
Thuja plicata , Western Red Cedar ,zone= 6 , sow 2m @ 39ºF, move to 70ºF for germ.
Thujopsis dolobrata , False arborvitae ,zone= 5 , difficult, give them to nature
Tilia americana , American Basswood ,zone= 3 , difficult, give them to nature
Tilia cordata , Small Leaved Lime ,zone= 3 , direct sow outdoors for germ. in about 17m
Tilia tomentosa , Silver linden ,zone= 6 , difficult, give them to nature
Tsuga canadensis , Canadian Hemlock ,zone= 4 , sow 3m @ 39ºF, move to 70ºF for germ.
Tsuga caroliniana , Carolina Hemlock ,zone= 4 , sow 3m @ 39ºF, move to 70ºF for germ.
Tsuga chinensis , Chinese Hemlock ,zone= 6 , sow 3m @ 39ºF, move to 70ºF for germ.
Tsuga heterophylla , Western Hemlock ,zone= 6 , sow 3m @ 39ºF, move to 70ºF for germ.
Tsuga mertensiana , Mountain Hemlock ,zone= ?, sow 3m @ 39ºF, move to 70ºF for germ.
Ulmus alata , Winged Elm ,zone= 6 , sow 3m @ 39ºF, move to 70ºF for germ.
Ulmus americana , American Elm ,zone= 3 , sow 3m @ 39ºF, move to 70ºF for germ.
Ulmus glabra , Wych Elm ,zone= 5 , sow 3m @ 39ºF, move to 70ºF for germ.
Ulmus parvifolia , Chinese Elm ,zone= 5 , sow 2m @ 39ºF, move to 70ºF for germ.
Ulmus pumila , Siberian Elm ,zone= 4 , sow 3m @ 39ºF, move to 70ºF for germ.
Ulmus rubra , Slippery Elm ,zone= 3 , sow 3m @ 39ºF, move to 70ºF for germ.
Vaccinium corymbosum , Highbush blueberry ,zone= 3 , direct sow outdoors
Viburnum dentatum , Arrowwood viburnum ,zone= 2 , sow 6m to 17m @ 68ºF night and 86ºF daytime temps, then 2m @ 39ºF, recycle
Viburnum dilatatum , Linden viburnum ,zone= 5 , sow 5m @ 70ºF, then 3m @ 39ºF, recycle
Viburnum lantana , Wayfaring Tree ,zone= 3 , direct sow outdoors
Viburnum lentago , Sheepberry ,zone= 2 , sow 5m to 9m @ 68ºF night and 86ºF daytime temps, then 2m to 4m @ 39ºF, recycle
Viburnum opulus , European cranberrybush ,zone= 3 , sow 2m to 3m @ 68ºF night and 86ºF daytime temps, then 2m @ 39ºF, recycle
Viburnum x burkwoodii , Burkwood viburnum ,zone= 3 , wash seeds 3x daily 7d, sow @ 70ºF in moist paper towels until radicles emerge, then direct sow outdoors
Vitex negundo , Chastetree ,zone= 6 , direct sow outdoors
Weigela floribunda , Japanese wisteria ,zone= 4 , direct sow outdoors
Weigela florida , Weigela ,zone= 5 , direct sow outdoors
Xanthoceras sorbifolium , Yellowhorn ,zone= 6 , sow @ 70ºF
Zanthoxylum americanum , Northern Prickly Ash ,zone= 3 , direct sow outdoors in the fall
Zelkova serrata , Japanese zelkova ,zone= 5 , sow 2m @ 39ºF, move to 70ºF for germ.
Zenobia pulverulenta , Dusty zenobia ,zone= 5, sow @ 70ºF on peat moss

References for Seed Germination of woodies:

Norman C Deno, "Seed Germination Theory and Practice", 2nd Ed. 1993, and Supplements #1 and #2  (these books describe actual germination experience for each species tried, but are not restricted to woodies.)

Michael A Dirr, "Manual of Woody Landscape Plants", 1975 and numerous revisions. (the Doctor is in: descriptions of woody plants and their cultivars, along with best propagation advice.)

James A Young and Cheryl G Young, "Seeds of Woody Plants in North America", 1992 (marvelous book on seed germination of woodies; see Appendix B for germination characteristics by genera; these general rules are invaluable.)

Sowing Seeds Indoors

The average gardener finds the optimal germination temperature for any seed printed on the seed packet or in the seed catalog.  Sometimes, the instructions offer only a month to sow outdoors, or the number of weeks before last frost to sow indoors.  When the sun warms the soil outdoors to the proper level, those seeds will germinate.  The term "indoors" usually refers to room temperature. But room temperature is different for every family, and for many families, setback thermostats heat the indoors to a significantly lower temperature at night.  What room temperature means is 68 to 72ºF held constant.  But it is soil temperature that invites the seeds to germinate, not air temperature.  Because of constant moisture loss to the atmosphere, the soil temperature is always cooler than the air temperature.  Remember that evaporation cools the media holding the moisture.  If your home is on the low side of 68 to 72ºF, your seeds will benefit from bottom heat.

As a general rule, seeds will germinate indoors where the soil temperature is held constant.  In nature, the soil temperature is usually lower at night. Therefore, an indoor drop in temperature at night of less than 10ºF will not significantly delay seedling emergence.  There are exceptions to every rule. Cleome seeds prefer oscillating temperatures.  Vinca rosea likes three days at 80ºF after which it will germinate at room temperature.  But, the exceptions are few.  To start seeds reliably indoors, one needs access to several environments.  The refrigerator can be relied on to supply 37 to 40ºF.  Your room temperature is another steady enrironment that will be ideal for some seeds.  There are just as many species however, that prefer 55ºF, 60ºF, 65ºF, 75ºF, or 80ºF, or even 85ºF in some cases.  The question for many beginning seed starters is how one provides alternative environments to room temperature.  

Cyclamen, Delphinium, and Geranium species, for example, prefer temperatures cooler than room temperature, and frequently can be started on windowsills. Capsicum, Impatiens, and Lycopersicon species, for example,  prefer temperatures warmer than room temperature, and usually do best started in heated propagators, on heat mats, on heating cables, the top of the refrigerator, or above a fluorescent light fixture where heat rises from the ballast.  Many gardeners have constructed propagating chambers along the lines of herb dryers.  A number of small light bulbs (7 to 15 watts) under the bottom shelf supply the heat, and the temperature can be controlled by the number of lights actually turned on.  Each shelf consists of sturdy hardware cloth to support the seed pots while permitting the warm air to circulate upwards.

Starting a wide range of species indoors requires the gardener to manage at least four temperature zones.  Besides the refrigerator and room temperature, I would suggest a 55 to 65 degree zone and a 75 to 80 degree zone.  But, alternative temperature zones are not available to many gardeners, and they might have to get some help from the great outdoors.

Let Nature Do The Work

Some seeds require more than one year to germinate.  Others, called multicycle germinators, require at least two cold stratification periods before germination; the hellebores are one example.  Most members of the Ranunculus family require temperatures very close to the freezing point of the seed (~19ºF) for destruction of germination inhibitors.  Some seed, like Cimicifuga require a long period of warm stratification before cold treatment. Other seed, like Myrrhis must be sown outdoors.  Sowing of these types of seeds should be done outdoors, both for your own convenience, and for the greater degree of success in the germination of difficult species.  But, I do not mean direct sowing in the ground necessarily, although that will be especially successful with Myrrhis, for example.  

There are some gardeners that sow all their perennial seeds in pots out of doors.  The pots must be protected from the sun and from loss of moisture, so there are some zones where it may not be practicable.  Algae formation is usually minimized by using a larger size granite grit to isolate the soil media from the atmosphere.  The special temperature zones required for some seeds are readily available as the seasons change, and if the gardener is in no particular hurry, there is much to be said for letting nature do the work.  I prefer indoor seed starting myself, but I did find it necessary to direct sow 8 species last fall, and to sow 18 additional species in pots to be covered with snow.  Those are what I call frost germinators.

Soilless Mixes & Amendments

The basic component of soilless mixes is sphagnum peat moss. The various amendments added to each mix include , coir, vermiculite, dolomitic limestone, fertilizer, trace elements, perlite, wetting agents, gypsum,  rock wool, calcine clay, and pine bark. There are several manufacturers who blend these materials together to produce a range of special purpose mixes for greenhouses, nurseries, and gardeners.  These mixes are quite variable across North America because of shipping costs. That is, the constituents are variable in nature, and there use will be heaviest in the region of their origin. Some of the popular brands include Terra-Lite, Metro Mix, Sunshine, and Pro-Mix.  Each mix comes in several grades, the difference lying in the percentage of each of the amendments. This article is directed to recreational gardeners who are sowing seeds indoors or in a hobby greenhouse, are looking for the best seed sowing medium and the latest technique.

Germination mix, plug mix, and starter mix are the terms applied to mixes formulated for seed germination.  Other formulations include growing mix, rock wool mix, bark mix (high porosity), and bark mix (low porosity).  For your suitability testing of product, stick to those mixes labeled germination, plug, or starter.  These mixes usually include the peat moss/bark/coir mixture plus perlite, vermiculite, dolomitic limestone, and a wetting agent.  Some germination mixes will also include some fertilizer and trace elements.  Fertilizer and trace elements are not required for seed germination.  I prefer a mix without them, however I do use a weak fertilizer solution at initial sowing.  The characteristics of a germination mix include a high water capacity (about 86%), an air capacity of 12 to 15%, and a Ph about 5.8    From this basic mix, you can custom make your own formulation.

Bark:

Southern pine bark and Northern softwoods are usually employed to increase bulk density and increase air space.  In addition, bark will slightly reduce the water holding capacity of the mix, and there is some evidence that bark imparts some disease resistance.  Bark is usually described as aged bark or as composted bark.  Insufficient aging or composting could result in excessive heating of the mix or draw excessive nitrogen, but these materials are usually tested thoroughly before use by reputible companies.  The fertilizer level of these mixes are usually amended with additional nitrogen.  I do not use bark mixes for seed germination, but find them attractive for potting-on in several cases.

Coir:

(pronounced "choir" as in church choir)  Coir dust is a by-product of the coconut fiber industry and is used in mixes to lessen the amount of peat required.  It has a high  air and water holding capacity.  Its nutrient-holding capacity is a bit less than peat, but it does contain significantly higher levels of soluble salts. The use of coir dust as a component of germination and plug mixes is dictated by the high cost of shipping peat down South.

Perlite:

Perlite is a natural heat expanded  volcanic mineral that is chemically inert, and will not alter the nutrient quality or the Ph of the material with which it is mixed. The particles provide excellent drainage, while trapping air and water on their irregular surfaces.  Perlite is usually sold in 4 cu. ft. bags for less than $10 by suppliers to the greenhouse and nursery industries, most of whom will also sell at retail.  Perlite is available in fine, medium, and coarse grades.  

The higher the total porosity of the mix, the greater the potential for providing water and air. Oxygen is essential to healthy root activity, but not more essential than moisture. Practical boundaries are 75% perlite/25% peat moss for lowest wet bulk density and 25% perlite/75% peat moss for highest wet bulk density. Finer grades of perlite decrease porosity of the mix, while coarse grades increase porosity.  For ease of transplanting tender seedlings, adequate levels of aeration and moisture, I have been using the coarse grade of perlite. It provides the additional benefit of maximum root oxegenation.

Added to your germination mix, perlite will improve drainage and may reduce the cost of the overall mix. Outdoors, perlite performs similarly to help hold nutrients from leaching in sandy soil and to improve aeration and drainage in heavy clay soils.  It can also be used as an insulating winter mulch if covered with about 2 inches of soil.

Vermiculite:

Vermiculite is a mica-type material that is mixed and heated to cause the accordion like particles to expand.  This expansion makes them capable of holding large amounts of plant available water and nutrients. As a seed covering, it helps maintain sufficient moisture at the growing medium surface for germination. Available in fine, medium, and coarse grades, I usually select the  medium grade, but rarely have use for this material except in potted plants. Vermiculite is usually sold in 4 cu. ft. bags for less than $12. Caution: Vermiculite is available at home centers and building supply companies as an additive for plaster and insulation in walls and ceilings. Do not use these products for soil conditioning. Construction grades of vermiculite do not absorb water well and are not handled properly during the manufacturing process to maintain a sterile product.  Make sure that the bag is labeled "horticultural."  There are three basic uses for vermiculite.  Added to your germination mix, it will improve water retention and may reduce the cost of the overall mix.  Finally, when added to sandy soil in the garden, water retention is greatly improved.  I prefer to use this material in potted plants only or in situations where seedling development time is long, as in bulb forming plants.

Wetting agents:

This is where the commercial mixes become distinguishable, one from another. Wetting agents are water absorbing polymers available in gel, liquid, or powder form.  The amount of wetting agent added to your germination mix determines the ability of the mix to absorb water from the bottom. Watering seedlings from the bottom is one of several techniques used to reduce the incidence of damping-off.  Therefore, I make bottom absorption my number one criteria in evaluating a commercial germination mix, and do not have to add wetting agents myself. They can be purchased to improve homebrew mixes, and make an excellent additive in gel form when repotting indoor plants. Peat and bark progressively lose their ability to retain and uniformly distribute water and chemicals to the rootzone. Wetting agents available from your distributor may include:

Soax made by Oasis Grower Products, 800-321-8286

PsiMatric made by Aquatrols, 800-257-7797 

Granite grit:

Sifted crushed granite is used as a feed additive to help birds and poultry to grind their food (since they don't have molars).  My feathered friends get theirs from the eave gutters where the grit from the roofing shingles tend to collect.  It is sold in feed stores in three grades. Chick grit (or chicken starter grit) is the fine (smallest) grade.  The bags are labeled "starter" or "fine", hence the name Chick grit. This is the size used as a seed topping.  The next larger size is labeled "grower" or "special pullet".  The largest size is about the size of a pea and carries the label "large" or "coarse" depending upon the supplier.  Cost in the Chicago area is about $4.75 for 50 lb. bag.  Chick grit is sometimes added to the germination mix to improve drainage, especially for alpines, but is usually used as a seed topping.

Other forms of chick starter grit are manufactured from oyster shell or calcium carbonate and can be used in the same manner, with some reservation as to longevity and the amount of long-term calcium release when the product is used for creating alpine soils. These are also offered in screened sizes and labeled in the same manner as granite grit. The "starter size" or "chick grit" of both of the above products is slightly smaller and lighter than granite grit, and therefore suitable for topping smaller seeds. Similarly, other products marketed under the names Terra-Green or Turface are inert sterile calcined mineral absorbent (high temperature processed ground up clay) which may be used as a seed topping or in mixes requiring "sharp" drainage.  Certain grades of silica sand, bank sand, and kitty-litter are also used in these applications, but I would experiment with them very sparingly.  A fine grade of aquarium gravel would be suitable too, but expensive. In some areas, granite grit may not be available due to freight costs, and you may find grit made from "quartzite". This substitute has proven itself the equivalent of granite grit in my own operation.

Adjusting your mix:

The germination mix I use is Sunshine #5 which is called a "plug mix".  It contains sufficient wetting agent for excellent bottom absorption when watering.  Regional distribution across North America may not be even.  In every area, there will be at least one good brand which offers at least one formulation that will be satisfactory.  Finding the best starter mix for you involves searching and testing.  Many suppliers will release one lb. samples for this purpose.

Because these mixes are relatively expensive ($15 to $23 for 4 cu. ft. compressed bale) and because Canadian sphagnum peat moss is not a renewable resource, I prefer to cut the prepared mix with cheaper sterile additives which improve the mix to my needs while lowering the average cost, a little. I add four parts plug mix to two parts perlite and perhaps one half part vermiculite. Sometimes, the seeds have special requirements, and I will make up a special mix just for them.  For example, when sowing Lisianthus, the seed company recommends three parts mix plus seven parts perlite. If I know in advance that a particular seedling is sensitive to damping-off (see the FAQ on seedling diseases), I will combine four parts mix with two or three parts perlite, and dispense with the vermiculite. Potted plants in the sun need more moisture retention, so I will increase the percentage of vermiculite, etc.  Adjusting your basic mix is a matter of "feel" based on your experience.  In some applications, I will add one or two parts of grit to the soil mix for plants requiring "sharp" drainage.

Seed sowing technique:

The fewer the number of seeds you plan to start, the greater the number of seed starting systems available for purchase.  As you increase your seed starting plans over the years, more and more of those seed starting systems become inadequate.  The pots and trays that I use are suitable to the scale at which I operate, that is, the sowing of 300 to 400 packets of seed per year. There are recreational gardeners sowing anywhere from 1 to 2000 packets of seed per year.  At some point, you will discover the need to sow seeds in communal rather than individual pots, especially where considerable numbers of seed types need conditioning before germination. Therefore, the method I describe is peculiar to the scale of my hobby, and may not be suitable for many gardeners.  

My communal pots are 3.5 inch square pots which are four inches deep.  The pot is filled with mix to a 3 inch depth, and tamped down lightly.  Nine to thirty seeds are sown on top of the mix, and covered with 1/16th inch to 1/4 inch of grit, depending upon the diameter of the seed.  Larger seeds get the heaviest topping. Seeds requiring light for germination are sown on top of 1/8 inch of grit, and watered into the topping and covered thinly with a very light dusting of oyster shell.  The "starter" or chick grit size of oyster shell is basically powder.  It has the advantage over silica sand in that it never cakes up. The pots are placed in a tepid water bath until the topping is fully moistened. Since these pots are disposable types, they are labeled on the sides with a pressure sensitive label showing plant identification, germination temperature, and growing-on temperature.  The seeds are sown from the palm of my left hand.  That is, the seed stock is placed there, and with the blade of a tiny pen knife, I pickup a one to four seeds at a time so that they can be distributed in the nine imaginary sowing squares in each pot. To control the distribution of very fine seeds, it is important to me to pick up exactly the number of seeds to be dropped into each sowing area.  I never broadcast sow.

After germination, the pots are moved to the proper location for growing-on temperature.  As soon as the seedlings have their first or second set of true leaves, depending upon vigor, they are transplanted to individual 2 1/4 inch seedling pots.  When the leaves of each plant begin to interfere with plants in adjacent pots, the seedlings are transplanted to 3 1/2 inch, then 5 inch, 6 inch, or 8 inch pots as necessary to maintain constant vegetative growth until it is time for setting out. Additional grit is applied as topping with each transplant to prevent the growth of algae and mosses, and to protect the crowns of the seedlings from excessive moisture. In climates where algal growth on the seed topping is excessive, you can use a product called Agribrom misted onto the topping at the rate of 15ppm. The additional medium added during transplanting to accomodate larger pots is the same germination mix through transfer to 3 1/2 inch pots. For transfer to larger size pots the additional medium added during transplanting is potting mix.  My potting mix is composed of 1/3rd germination mix plus 1/3rd compost plus 1/3rd garden soil. There are many variations of this practice for seed conditioning and special requirements.

After the first transplant, the seedlings need nutrients and trace elements.  The trays are watered from a solution which I make up in 1/2 gallon plastic bottles containing one half tablespoon of household vinegar and 1/8th to 1/4 teaspoon of general purpose fertilizer.  The purpose of the vinegar is to make a slight adjustment in Ph since my water supply tests out at 7.6 on average. Again, there are many variations on this practice based on the Ph preference of each type of plant. Seedling trays are moved to protected positions out of doors, under the carport, in the greenhouse, on the patio, etc. as soon as possible.

The following is excerpted from the practice of a popular nursery owner in Southern Illinois:

"I use Scott's Pro Metro Mix.  I sift it for seed sowing to remove the large bark pieces through a 1/2 inch screen.  Nothing added, unless I am doing alpines, in which case, I add 1/2 part grit.  My transplant mix is one part Metro mix, one part peat, 1/2 part vermiculite, 1/2 part perlite, and one gallon of silica sand for each  3 cu. ft. bag of mix.  For alpines, I add more perlite and some grit.

I use grit as a pot topping for seed growing.  One of the main reasons is to control the various fungal diseases grouped under the general heading of damp-off.  Seedlings come up through the grit easily, and since it dries quickly, and doesn't hold much moisture, the incidence of damp-off is much less than when using moisture retentive substances such as vermiculit or sphagnum.  It also helps to control the growth of lichen and moss under the lights.  I also use it on cuttings.  In addition, I use grit as a top dressing on those plants that dislike moisture around the crowns.  Most of those are rock garden plants.

If the seeds need light, just cover the post with a very light layer of grit, just until you can't see the soil.  For very fine seeds, such as begonia or campanula, I sow the seeds on top, then use a fine mist sprayer to wash the seeds down into the grit.  I also find it useful, when sowing like this, to sprinkle a very thin layer of white silica sand to help hold in moisture. Just as with other seed toppings, you can eventually tell by looking what pots need watering.  The grit does not stay completely dry, and as with soil, changes color when the pots begin to get dry.  I find that the watering is on a much more regular basis with grit as a topping.  Almost all of the pots dry out in the same intervals.  I end up watering indoor sown seedling pots about twice per month.  I also mist them once a day with a mist setting on the hose sprayer to help break up the seed coats which sometimes prevent the cotyledons from getting free."

Damping-off

The single term used to describe underground, soil line, or crown rots of seedlings due to unknown causes is damping-off . The term actually covers several soil borne diseases of plants and seed borne fungi.  

Rhizoctonia root rot (Rhizoctonia solani) is a fungal disease which causes damping-off of seedlings and foot rot of cuttings.  Infection occurs in warm to hot temperatures and moderate moisture levels.  The fungi is found in all natural soils and can survive indefinitely.  Infected plants often have slightly sunken lesions on the stem at or below the soil line.  Transfer of the fungi to the germination room or greenhouse is easily accomplished by using outdoor gardening tools inside or vice versa.  The germination room should not be used for mixing potting soils or transplanting seedlings as a general rule.

Pythium Root Rot (Pythium spp.) is similar to Rhizoctonia in that it causes damping-off of seedlings and foot rot of cuttings.  However, infection occurs in cool, wet, poorly-drained soils, and by overwatering.  Infection results in wet odorless rots.  When severe, the lower portion of the stem can become slimy and black.  Usually, the soft to slimy rotted outer portion of the root can be easily separated from the inner core.  Species of Pythium can survive for several years in soil and plant refuse.

Phytophthora root rot (Phytophthora spp.) are usually associated with root rots of established plants but are also involved in damping-off.  These species enter the root tips and cause a water-soaked brown to black rot similar to Pythium. These fungi survive indefinitely in soil and plant debris.

Black root rot (Thielaviopsis basicola) is a problem of established plants.  It does not occur in strongly acid soils with a pH of 4.5 to 5.5.  It usually infects the lateral roots where they just emerge from the taproot.  The diseased area turns dark brown, and is quite dry.  The fungi survive for 10 years or more in soil.

Miscellaneous fungi causing similar symptoms include Sclerotinia (white mold), Sclerotium rolfsii, Macrophomina phaseoli, some species of Botrytis (gray mold), Aphonomyces, Fusarium, Cylindrocladium, and others.  Hence the need for the collective term known as damping-off.

Symptoms of Damping-off:

Seeds may be infected as soon as moisture penetrates the seed coat or a bit later as the radicle begins to extend, all of which rot immediately under the soil surface (pre-emergence damping-off). This condition results in a poor, uneven stand of seedlings, often confused with low seed viability. Cotyledons may break the soil surface only to whither and die or healthy looking seedlings may suddenly fall over (post-emergence damping-off).  Infection results in lesions at or below the soil line. The seedling will discolor or wilt suddenly, or simply collapse and die.  Weak seedlings are especially susceptible to attack by one or more fungi when growing conditions are only slightly unfavorable. Damping-off is easily confused with plant injury caused by insect feeding, excessive fertilization, high levels of soluble salts, excessive heat or cold, excessive or insufficient soil moisture, or chemical toxicity in air or soil.

Above ground symptoms of root rot include stunting, low vigor, or wilting on a warm day. Foliage of such plants may yellow and fall prematurely starting with the oldest leaves.  The roots of a diseased plant will have some shade of brown or black and evidence of water-soaking.  Healthy roots are fibrous appearing and are usually white or tan in color. These symptoms are easily confused with severe mite, aphid, scale infestations, or root-feeding by nematodes or insect larvae. Environmental factors such as accumulated salts in the soil, insufficient light or nitrogen, potbound roots, cold drafts, etc. can be eliminated only by examination of the roots.

Damping-off diseases can be prevented:

• Purchase disease free plants and seeds.  Know your supplier.  Do not be afraid of fungicidal coatings on seeds which will be direct sown out doors in cold soils, such as corn and peas. Seed borne disease can also be avoided by soaking the seeds for 15 minutes in a bleach soak (one teaspoon per quart of water) prior to sowing.
• Use sterile well drained soil mediums. See article on soil mixes. Try to maintain a soil mix pH at the low end of the average scale, i.e. 6.4 pH is less susceptible to root rot than a pH of 7.5.  Commercially prepared germination mixes usually have a pH around 5.5.  As you water the seed pots and your seedlings with tap water (which in many municipalities is quite alkaline), the pH in your pots gradually increases as does the susceptibility to damping-off diseases.  Know the pH of your tap water, and condition it if necessary to maintain a lower pH while the plants are still in the germination room.  I prefer the use of vinegar at the rate of one tablespoon per gallon of water.
• Plants must not have their crowns below the soil line.  Seeds must not be covered more than 4 times the thickness of the seed.
• Use plant containers with drainage holes, water from the bottom only, and avoid excess watering. Do not allow pots to stand in water as excess water cannot drain and the roots will be starved for oxygen bringing all growth to a halt.
• Avoid overcrowding  and overfeeding of plants.  It is important to maintain constant levels of growth through proper lighting and complete control of the growing environment.
• Avoid working with plants (taking cuttings or transplanting) when the soil is wet. Do not use water from ditches or drainage ponds or rain barrels in the germination room.
• Avoid spreading soil from infested areas or tools which have been used out of doors. Disinfect tools and containers with one part bleach in four parts water or with 70 percent rubbing alcohol (isopropyl).
• In the germination room,  sow all your seeds on the surface of the media, then cover the seeds to necessary depth with a material which is less likely to harbor fungi than the media itself.  Use one or more of the following seed toppings instead of soil mix:
  • milled sphagnum moss
  • chick grit
  • course sand or fine aquarium gravel
  • composted hardwood bark (steamed)
• In the germination room, mist seedlings in communal pots or flats once or twice per day with water containing a known anti-fungal agent such as:
  • Captan (or other approved fungicide) especially if walls or floors are damp, or
  • Cheshunt compound, a copper/aluminum formulation, or
  • chamomile tea, or
  • clove tea, or
  • a  one-time light dusting of powdered cinnamon on the soil surface, or
  • a one-time light dusting of powdered charcoal on the soil surface, or
  • if stinging nettle is endemic in your area, make a fermented infusion to use like clove tea.           These last five actions are suggested by sufficient anecdotal evidence to prove  the existence of a low level of fungicidal activity.  I would not hesitate to use them in germination environments which have no history of damping-off diseases.
• Rotate plantings on a 2 to 3 year schedule using plants from different families in order to starve out existing pathogens.
• Provide constant air movement not tied in with the light timer.  Air should move freely 24 hours per day, but not directly aimed at the plants.  This helps the seedlings to aspirate, and excess soil moisture to wick.  If you do everything else right but do not provide plenty of air movement, you will still get damping-off.

So, what do I do?  Answer:  all of the above, all of the time.

Damping-off diseases can be controlled:

Fungicides may be applied as a soil drench after planting.  They may be incorporated into the soil before planting as a dust. They can be sprayed in mist form on all seedlings as a precaution until they have been transplanted into individual pots. Once transplanted, only those seedlings known to be especially sensitive to damping-off need be misted with fungicide daily until the first or second seed leaves have emerged.  The following chemicals are not recommended for use by the average recreational gardener, but may still be available for use (if not yet banned), providing  the manufacturer's instructions are followed to the letter.

Captan (sold as Captan) controls most pathogens, but not Rhizoctonia.

Metalaxyl (sold as Subdue or Apron) controls Pythium, Phytophthora,  and Aphanomyces.

Iprodione (sold as Chipco) controls most pathogens, but not Pythium, Phytophthora, or Aphanomyces.

Etridiazole and Thiophanate-methyl (sold as Banrot) controls most all pathogens.

PCNB-etridiazole (sold as SA-Terraclor or Super-X) good general purpose fungicide.

PCNB-quintozene (sold as Terraclor, Fungi-clor, or PCNB) controls Rhizoctonia and Sclerotinia species.

Fosetyl-A1 (sold as Aliette) controls Pythium, Phytophthora, & Aphanomyces.

Well, you get the idea.  There are too many to list, and they go on and off the market very quickly (mostly because they are very dangerous when used improperly, and some are too dangerous to have been put on the market at all.)

So, what do I use?  Answer: Just enough Captan as needed.  

SPECIAL TREATMENT TIPS

 Hard Seeds-Chipping

Some seeds, e.g. Sweet peas, pomaea etc., have hard seed coats which prevent moisture being absorbed by the seed. All that is needed is for the outer surface to be scratched or abraided to allow water to pass through. This can be achieved by chipping the seed with a sharp knife at a part furthest away from the 'eye', by rubbing lightly with sandpaper or with very small seed pricking carefully once with a needle etc.

Hard Seeds-Soaking

Soaking is beneficial in two ways; it can soften a hard seed coat and also leach out any chemical inhibitors in the seed which may prevent germination. 24 hours in water which starts off hand hot is usually sufficient. If soaking for longer the water should be changed daily. Seeds of some species (e.g. Cytisus, Caragana, Clianthus) swell up when they are soaked. If some seeds of a batch do swell within 24 hours they should be planted immediately and the remainder pricked gently with a pin and returned to soak. As each seed swells it should be removed and sown before it has time to dry out.

Stratification (cold treatment)

Some seeds need a period of moisture and cold after harvest before they will germinate-usually this is necessary to either allow the embryo to mature or to break dormancy. This period can be artificially stimulated by placing the moistened seed in a refrigerator for a certain period of time (usually 3- 5 weeks at around 41 F). With tiny seeds it is best to sow them on moistened compost, seal the container in a Polythene bag and leave everything in the refrigerator for the recommended period. However, larger seeds can be mixed with 2-3 times their volume of damp peat, placed direct into a Polythene bag which is sealed and placed in the refrigerator. Look at seeds from time to time. The seeds must be moist whilst being pre-chilled, but it doesn't usually benefit them to be actually in water or at temperatures below freezing.

Light also seems to be beneficial after prechilling and so pre-chilled seeds should have only the lightest covering of compost over them, if any is required, and the seed trays etc. should be in the light and not covered with brown paper etc.

Double Dormancy

Some seeds have a combination of dormancy's and each one has to be broken in turn and in the right sequence before germination can take place; for example, some Lilies, Tree paeonies, Taxus need a three month warm period (68-86'F) during which the root develops and then a three month chilling to break dormancy of the shoots, before the seedling actually emerges. Trillium needs a three month chill followed by three months of warmth and then a further three month chill before it will germinate.

Outdoor treatment

The above mentioned methods accelerate the germination process and help to prevent seeds being lost due to external hazards (mice, disease, etc.) but outdoor sowing is just as effective albeit longer. The seeds are best sown in containers of free draining compost and placed in a cold frame or plunged up to their rim outdoors in a shaded part of the garden, preferably on the north side of the house avoiding cold drying winds and strong sun.

Recent tests show that much of the beneficial effects of pre-chilling are lost if the seed is not exposed to light immediately afterwards. We therefore recommend sowing the seeds very close to the surface of the soil and covering the container with a sheet of glass. An alternative method especially with larger seeds, is to sow the seed in a well prepared ground, cover with a jam jar and press this down well into the soil so that the seeds are enclosed and safe from predators, drying out etc.

We've received so many great feedback posts from our customers! Here are a few of our recent favorites we'd like to share.

	Great Communication, fast ship, the rest is up to me, wish me luck.	Buyer: hannahkyle ( 370)	May-31-08 12:53
	10+ ORANGE LACE-LEAF JAPANESE MAPLE Tree Seeds - Bonsai (#380031562120)	US $2.01	View Item

	Thanks! Goes above and Beyond to make customer happy. Customer for life!!	Buyer: budda*belly ( 388)	May-30-08 00:55
	200+ RARE BONSAI TREE SEEDS 19 VARIETY + JAPANESE MAPLE (#380024380418)	US $35.00	View Item

	Très bonne transaction; vendeur très sérieux et généreux.	Buyer: uta1511 ( 191)	May-29-08 10:08
	10 CUT-LEAF FULLMOON JAPANESE MAPLE Tree Seeds - Bonsai (#380026979618)	US $6.00	View Item

	great deal great shipping would do again with out a doubt AAA+++	Buyer: texasdnw ( 19)	May-27-08 19:51
	200+ RARE BONSAI TREE SEEDS 17 VARIETY + JAPANESE MAPLE (#380026625171)	US $27.58	View Item

	Thank you. Above and beyond service. A++++++++++++++++++++	Buyer: marlab! ( 278)	May-23-08 20:08
	10 CUT-LEAF FULLMOON JAPANESE MAPLE Tree Seeds - Bonsai (#380024324382)	US $28.65	View Item

	Very well packed and just as described, excellent service. Thank you very much!	Buyer: bam.905 ( 12)	May-15-08 16:44
	10 CUT-LEAF FULLMOON JAPANESE MAPLE Tree Seeds - Bonsai (#380022709374)	US $5.00	View Item

	Fast prefessional & caring man. Thank you will keep in touch growing them now.	Buyer: williamvas ( 9 )	May-11-08 05:41
	170 RARE JAPANESE MAPLE TREE SEEDS - 18 VARIETY BONSAI (#380017254098)	US $35.00	View Item

	Great seeds, well packed, arrived safe and dry, smooth transaction, A+++	Buyer: susierehabrn ( 322)	May-08-08 17:12
	200+ RARE BONSAI TREE SEEDS 19 VARIETY + JAPANESE MAPLE (#380024380425)	US $33.72	View Item

	Seeds arrived quickly! Looking forward to planting! Thanks for the bonus pack!	Buyer: closet4sale ( 529)	May-05-08 13:48
	10 RED JAPANESE MAPLE Tree Seeds - Atropurpureum Bonsai (#380019544041)	US $3.05	View Item

Thank you everyone!

William

So What is a Seed?

A seed is an embryo plant and contains within itself virtually all the materials and energy to start off a new plant. To get the most from one's seeds it is important to understand a little about their needs, so that just the right conditions can be given for successful germination.

Storage of Your New Seeds

The proper storage of your seeds is very important to insure they are viable when planted.  Almost all seeds should be stored in a cool, dry location away from sunlight.  The paper envelopes your seeds came in are best left sealed until you are ready to use them.  Remember that your seeds are alive!  It is best to you them as soon as possible.  Many tree seeds will be viable for many years but the chance of germination is less with each passing year.

Time to Plant, What Should I be Careful of?

One of the most usual causes of failures with seed is sowing too deeply.  A seed has only enough food within itself for a limited period of growth and a tiny seed sown too deeply soon expends that energy and dies before it can reach the surface.  Base how deeply you sow your seeds on the size of the seed itself.  Larger seeds should be sown deeper than smaller ones.

Watering

Another common cause is watering. Seeds need a supply of moisture and air in the soil around them. Keeping the soil too wet drives out the air and the seed quickly rots, whereas insufficient water causes the tender seedling to dry out and die.  Watering of containers of very small seeds should always be done from below, allowing the water to creep up until the surface glistens.  This prevent the small seeds from washing away and disturbs them the least.

Temperature

Most seeds will of course only germinate between certain temperatures. Too low and the seed takes up water but cannot germinate and therefore rots, too high and growth within the seed is prevented. Fortunately most seeds are tolerant of a wide range of temperatures but it is wise to try to maintain a steady, not fluctuating temperature. A seed starter heat mat is an excellent investment and can greatly increase the germination percentage.  Once several of the seeds start to germinate the temperatures can be reduced by about 5 degrees F and ventilation and light should be given.

What is Dormancy?

Some perennials and tree and shrub seeds can be very slow and erratic in germination. This may sometimes be due to seed dormancy, a condition which prevents the seed from germinating even when it is perfectly healthy and all conditions for germination are at optimum. The natural method is to sow the seeds out of doors somewhere where they will be sheltered from extremes of climate, predators, etc. and leave them until they emerge, which may be two or three seasons later. Dormancy, however, can be broken artificially and is explained in the detailed germination instructions included with every order from JF Exotic Seed.