Scarification, Stratification and Soaking Seeds

Many seeds require pre-treatment before they are sowed. The three most common treatments are scarification, stratification and soaking. These treatments mimic the type of exposure seeds would experience in the wild.

Seeds undergo a period of dormancy which protects the seed from germinating at the wrong time which could kill it. Once the right conditions are met, the seed germinates. Tough outer coats can protect the seed from the elements. In the wild, extended exposure to moisture will eventually wear the coat down, allowing water to penetrate.

In the wild, seeds will experience a winter period, and germination is triggered once the weather warms up. As our seeds are kept in a constant temperature, they do not experience a period of cold. Stratification involves storing seeds in a refrigerator for weeks or months to simulate winter. They may be kept in moist paper towels or dry.


Some seeds have a tough outer coat that needs to be worn down to let moisture in and trigger germination. There are several ways to scarify seeds, the most common method is to use sandpaper or a nail file to gently rough up the outer coat.


Stratification is a period of enforced cold that mimic winter and may be moist or dry. The period of stratification differs between species and can range from two weeks to two months.


Soaking is another method to soften a seed’s coat and allows it to germinate faster. There are several methods to soak including water, and chemicals.

Are these treatments necessary?

Not always, but following these treatments will increase your germination rate, resulting in more viable plants. I have sowed a number of seeds that require cold stratification without doing so, and still had success. But,


African daisy (Arctotis stoechadifolia) No No No
African daisy (Osteospermum spp.) Yes No No
Alfalfa (Medicago sativa) Yes No Yes
Alyssum (Lobularia maritima) No No No
Amaranth (Amaranthus spp.) Yes No No
Amethist flower (Browallia spp.) No No No
Anise hyssop (Agastache foeniculum) No Yes No
Armenian cucumber (Cucumis melo var. flexuosus) No No No
Arnica (Arnica montana) No Yes No
Artichoke (Cynara cardunculus var. scolymus) No Yes Yes
Aspagagus (Asparagus officinalis) No Yes Yes
Aster (Aster spp.) No No No
Baby’s breath (Gypsophila spp.) No No No
Balloon flower (Platycodon grandiflorus) No No No
Basil (Ocimum basilicum) No No Yes
Bear’s breeches (Acanthus mollis) No No Yes
Bee balm (Monarda didyma) No No No
Beetroot (Beta vulgaris) No No Yes
Begonia (Begonia spp.) No No No
Bellflower (Campanula spp.) No Yes No
Bells-of-Ireland (Moluccella laevis) No Yes No
Berberis (Berberis spp.) No Yes No
Bergamot (Monarda didyma) No No No
Betony (Stachys officinalis) No Yes No
Bilberry (Vaccinium myrtillus) No Yes No
Black-eyed Susan (Rudbeckia hirta) No Yes No
Bleeding heart (Dicentra spectabilis) No Yes No
Blanket flower (Gaillardia x grandiflora) No No No
Bloodroot (Sanguinaria canadensis) No Yes Yes
Blue felecia bush (Felicia amelloides) No Yes No
Blue vervain (Vebena hastata) No Yes No
Bok choy (Brassica rapa subsp. chinensis) No No No
Boltonia (Boltonia spp.) No No No
Boneset (Eupatorium perfoliatum) No Yes No
Borage (Borago officinalis) No Yes No
Broad bean (Vicia faba) Yes Yes No
Broccoli (Brassica oleracea var. italica) No No No
Brussels sprouts (Brassica oleracea var. gemmifera) No No No
Bugloss (Anchusa capensis) No Yes No
Burnet (Sanguisorba minor) No Yes No
Butter daisy (Melampodium
No No No
Butterfly bush (Buddleja spp.) No Yes No
Butterfly flower (Schizanthus spp.) No No No
Butterfly pea (Clitoria ternatea) Yes No Yes
Butterfly weed (Asclepias tuberosa) No Yes Yes
Cabbage (Brassica oleracea var. capitata) No No No
Calendula (Calendula officinalis) No No No
Californian poppy (Eschscholzia californica) No No No
Camas (Camassia spp.) No Yes No
Candytuft (Iberis spp.) No No No
Canterbury bells (Campanula medium) No Yes No
Cape jewels (Nemesia strumosa) No No No
Capsicum (Capsicum annuum) No No No
Carnation (Dianthus spp.) No No No
Carob (Ceratonia siliqua) Yes No No
Carrot (Daucus carota) No No Yes
Catnip/catmint (Nepeta spp.) No Yes
Cauliflower (Brassica oleracea var. botrytis) No No No
Celeriac (Apium graveolens var. rapaceum) No No No
Celery (Apium graveolens) No No No
Chamomile (Matricaria chamomilla) No Yes No
Chicory radicchio (Cichorium intybus var. foliosum) No No No
Chilean bellflower (Lapageria rosea) No Yes No
Chilli (Capsicum spp.) No No No
Chives (Allium schoenoprasum) No No No
Chinese aster (Callistephus chinensis) No No No
Chinese blackberry lily (Belamcanda
No Yes No
Chinese cabbage (Brassica rapa subsp. pekinensis) No No No
Chinese forget-me-not (Cynoglossum
No Yes No
Chinese lantern (Physalis alkekengi) No Yes No
Chrysanthemum (Chrysanthemum spp.) No No No
Clematis (Clematis spp.) No Yes No
Climbing bean (Phaseolus coccineus) No No Yes
Cliquefoil (Potentilla spp.) No No No
Cohosh (Cimicifuga spp.) No Yes Yes
Columbine (Aquilegia spp.) No No No
Common rockrose (Helianthemum nummularium) No No No
Common sneezeweed (Helenium autumnale) No No Yes
Comfrey (Symphytum spp.) No Yes No
Coral bell (Heuchera spp.) No Yes No
Coriander (Coriandrum sativum) No No No
Corncockle (Agrostemma githago) No No No
Cornflower (Centaurea cyanus) No No No
Coriander (Coriandrum
No Yes Yes
Cosmos (Cosmos bipinnatus) No No No
Cress (Lepidium sativum) No No No
Cucamelon (Melothria scabra) No No No
Cucumber (Cucumis sativus) No No No
Cup and saucer vine (Cobaea scandens) No No Yes
Cupflower (Nierembergia spp.) No No No
Cupid’s bow (Achimenes spp.) Yes No No
Cupid’s dart (Catananche caerulea) No No No
Cyclamen (Cyclamen spp.) No No Yes
Dahlberg daisy (Thymophylla tenuiloba) No No No
Dahlia (Dahlia spp.) No No No
Delphinium (Delphinium elatum) No Yes No
Dill (Anethum graveolens) No Yes No
Eastern redbud (Cercis
Yes Yes Yes
Echinacea (Echinacea spp.) No Yes Yes
Edeiweiss (Leontopodium
No No No
Eggplant (Solanum melongena) No No No
Elderberry (Galium aparine) No Yes No
English daisy (Bellis perennis) No No No
Endive (Cichorium endivia) No No No
Evening primrose (Oenothera spp.) No No Yes
Everlasting (Helichrysum bracteatum) No No No
False goat’s beard (Astilbe spp.) Yes No No
False indigo (Amorpha spp.) Yes Yes Yes
False sunflower (Heliopsis spp.) No Yes No
Fan flower (Scaevola aemula) No No No
Fennel (Foeniculum vulgare) No Yes Yes
Fenugreek (Trigonella foenum-graecum) Yes No No
Feverfew (Tanacetum parthenium) No No No
Firecracker flower (Crossandra infundibuliformis) No No Yes
Flax (Linum usitatissimum) No No No
Fleabane (Erigeron spp.) No No No
Floss flower (Ageratum houstonianum) No Yes No
Forget-me-non toxict (Myosotis spp.) No No No
Foxglove (Digitalis spp.) No Yes No
Foxtail lily (Eremurus robustus) Yes Yes Yes
Fuscia (Fuchsia spp.) No Yes Yes
Garden heliotrope (Heliotropium spp.) Yes Yes No
Gay feather (Liatris spp.) No Yes No
Gazania (Gazania spp.) No No No
Gentium (Gentiana spp.) No Yes No
Geranium (Pelargonium spp.) Yes No No
Gerbera (Gerbera spp.) No No No
Geum (Geum spp.) Yes Yes No
Ginseng (Panax spp.) No Yes No
Globe amaranth (Gomphrena globosa) No No No
Globeflower (Trollius spp.) No Yes No
Gloxinia (Sinningia speciosa) No No No
Goldencup (Hunnemannia fumariifolia) No No Yes
Goldenrod (Solidago spp.) No Yes No
Goldenseal (Hydrastis canadensis) No Yes Yes
Goldentuft (Aurinia saxatilis) No No No
Heather (Calluna vulgaris) No No No
Hellebore (Helleborus spp.) No Yes No
Hemp agrimony (Eupatorium cannabinum) No Yes No
Hibiscus (Hibiscus spp.) No Yes No
Hollyhock (Alcea rosea) No Yes No
Hydrangea (Hydrangea spp.) No No No
Iceland poppy (Papaver nudicaule) No No No
Impatiens (Impatiens spp.) No No No
Jacob’s ladder (Polemonium spp.) No No No
Juniper (Juniperus spp.) Yes Yes Yes
Kale (Brassica oleracea var. sabellica) No No No
Kohlrabi (Brassica oleracea var. gongylodes) No No No
Laceflower (Trachymene coerulea) No No No
Lady’s mantle (Alchemilla spp.) No No No
Ladys purse (Calceolaria spp.) No No No
Larkspur (Consolida ambigua) No Yes No
Lavender (Lavandula spp.) No Yes No
Leek (Allium ampeloprasum var. porrum) No No No
Lemon balm (Melissa officinalis) Yes Yes No
Lemongrass (Cymbopogon citratus) No No No
Leopard plant (Ligularia spp.) No No Yes
Leopard’s bane (Doronicum cordatum) No No No
Lettuce (Lactuca sativa) No No No
Licorice (Glycyrrhiza glabra, G. uralensis) Yes Yes No
Lilac (Syringa spp.) No Yes Yes
Linaria (Linaria spp.) No No No
Lisianthus (Eustoma grandiflorum) No No No
Livingstone daisy (Dorotheanthus bellidiformis) No No Yes
Lobelia (Lobelia spp.) No No No
Lomatium (Lomatium dissectum) Yes Yes No
Love-lies-bleeding (Amaranthus caudatus) Yes Yes Yes
Lupine (Lupinus spp.) Yes Yes Yes
Madagascar periwinkle (Catharanthus roseus) No No No
Maltese cross (Lychnis chalcedonica) No Yes No
Marigold (Tagetes spp.) No No No
Marshmallow plant (Althaea officinalis) No Yes No
Masterwort (Astrantia spp.) No Yes No
Meadowsweet (Filipendula ulmaria) No Yes No
Mexican creeping zinnia (Sanvitalia
No No No
Mexican sunflower (Tithonia spp.) No No No
Mignon toxicnette (Reseda odorata) No No No
Milkvetch (Astragalus spp.) Yes Yes No
Milkweed (Asclepias spp.) No Yes No
Mizuna (Brassica rapa var. Laciniifolia) No No No
Monkey flowers (Mimulus spp.) No Yes No
Monk’s hood (Aconitum spp.) No Yes No
Morning glory (Convolvulus spp.)
Yes No No
Motherwort (Leonurus cardiaca) No Yes No
Mountain mint (Pycnanthemum virginianum) No Yes No
Mugwort (Artemisia vulgaris) No Yes No
Mullein (Verbascum) No Yes No
Musk mallow (Malva moschata) No No No
Mustard (Brassica nigra) No No No
Nasturtium (Tropaeolum majus) Yes No Yes
Nemesia (Nemesia spp.) No No No
Nemophila (Nemophila spp.) No No No
Nigella (Nigella damascena) No No Yes
Obedient plant (Physostegia virginiana) No Yes No
Okra (Abelmoschus esculentus) Yes No Yes
Oregano (Origanum
No Yes No
Pansy (Viola tricolor var. hortensis) No Yes No
Curly parsley (Petroselinum crispum) No No No
Continental parsley (Petroselinum
crispum neapolitanum)
No No No
Pea (Pisum sativum) Yes No Yes
Pearly everlasting (Anaphalis margaritacea) No Yes No
Pentstemon (Penstemon hartwegii) No Yes No
Peony (Paeonia spp.) Yes Yes Yes
Persian violet (Exacum affine) No No No
Peruvian lily (Alstroemeria spp.) No Yes Yes
Petunia (Petunia spp.) No No No
Phlox (Phlox spp.) No Yes No
Pincushion flower (Scabiosa spp.) No Yes No
Plantago (Plantago rugelii) No Yes No
Poppy (Papaver spp.) No Yes Yes
Portulaca (Portulaca spp.) No No No
Potato bean (Apios americana) Yes Yes Yes
Pride of Madeira (Echium candicans) No No No
Primrose (Primula spp.) No Yes No
Purple rock cress (Aubrieta deltoidea) No No No
Pumpkin (Cucurbita spp.) No No Yes
Queen Anne’s lace (Daucus carota) No No No
Radish (Raphanus sativus) No No No
Rhubarb (Rheum rhabarbarum) No No Yes
Rock cress (Arabis spp.) No No No
Rocket (Eruca vesicaria ssp. sativa) No No No
Rockmelon (Cucumis melo var. cantalupensis) No No Yes
Rosemary (Salvia rosmarinus) No Yes No
Sage (Salvia officinalis) No Yes No
Saint John’s wort (Hypericum perforatum) No Yes Yes
Salvia (Salvia officinalis) No No No
Satin flower (Clarkia amoena) No No No
Savory (Satureja hortensis) No No No
Shooting star (Dodecatheon meadia) No No No
Sea holly (Eryngium spp.) No Yes No
Sea kale (Crambe maritime) No Yes No
Shasta daisy (Leucanthemum x superbum) No No No
Silver beet (Beta vulgaris var. cicla) No No Yes
Snapdragon (Antirrhinum majus) No No No
Snow-in-summer (Cerastium tomentosum) No No No
Society garlic (Tulbaghia
No No No
Speedwell (Veronica spp.) No Yes No
Spider flower (Cleome hassleriana) No Yes Yes
Spinach (Spinacia oleracea) No No No
Spring onion (Allium fistulosum) No No No
Squash (Cucurbita spp.) No No Yes
Statice (Limonium sinuatum) No No No
Stinging nettle (Urtica dioica) No Yes No
Stock (Matthiola incana) No No No
Stoke’s aster (Stokesia laevis) No No No
Sunflower (Helianthus spp.) Yes Yes Yes
Swan river daisy (Brachyscome iberidifolia) No No No
Swede (Brassica napus) No No No
Sweet cicily (Myrrhis odorata) No Yes No
Sweet pea (Lathyrus odoratus) Yes No Yes
Sweet rocket (Hesperis
No No No
Tarragon (Artemisia dracunculus) No No No
Thyme (Thymus vulgaris) No Yes No
Tomato (Solanum lycopersicum) Yes No Yes
Trumpet flower (Incarvillea spp.) No No No
Turnip (Brassica rapa subsp. rapa) No No No
Tweedia (Oxypetalum coeruleum) No No No
Twinspur (Diascia spp.) No No No
Valarian (Valeriana officinalis) No Yes No
Verbena (Verbena spp.) No Yes No
Viola (Viola spp.) No Yes No
Virginian stock (Malcolmia maritima) No No No
Wallflower (Erysimum cheiri, syn. Cheiranthus cheiri) No No No
Watermelon (Citrullus lanatus) Yes No Yes
Wild garlic (Allium ursinum) No Yes No
Wild indigo (Baptisia spp.) Yes Yes Yes
Wishbone flower (Torenia fournieri) No No No
Xeranthemum (Xeranthemum
No No No
Yarrow (Achillea spp.) No Yes No
Zinnia (Zinnia spp.) No No No
Zucchini (Cucurbita pepo) Yes No Yes