Seeds are in a dormant state until the right conditions occur which triggers the end of dormancy. There are a number of critical factors that determine when a seed will germinate including moisture, oxygen and the right soil temperature. Some seeds also require a period of cold, known as cold stratification. This mimics the normal winter a seed would usually experience before germinating once temperatures warm up in spring.
We recommend gardeners purchase a soil temperature thermometer to check soil temperature before sowing seeds. These are available from most nurseries or online.
Celsius |
Fahrenheit |
Stratification? |
|
| African daisy (Arctotis stoechadifolia) | 18 – 21 | 65 – 70 | No |
| African daisy (Osteospermum spp.) | 21 – 24 | 70 – 75 | No |
| Alyssum (Lobularia maritima) | 12 – 23 | 55 – 75 | No |
| Amethist flower (Browallia spp.) | 18 – 21 | 65 – 70 | No |
| Aster (Aster spp.) | 18 – 23 | 65 – 75 | No |
| Baby’s breath (Gypsophila spp.) | 15 – 18 | 60 – 65 | No |
| Balloon flower (Platycodon grandiflorus) | 16 – 20 | 60 – 68 | No |
| Bear’s breeches (Acanthus mollis) | 18 – 21 | 65 – 70 | No |
| Bee balm (Monarda didyma) | 16 – 21 | 60 – 70 | No |
| Begonia (Begonia spp.) | 18 – 21 | 65 – 70 | No |
| Bellflower (Campanula spp.) | 21 – 23 | 70 – 75 | Yes |
| Bells-of-Ireland (Moluccella laevis) | 13 – 18 | 55 – 64 | Yes |
| Black-eyed Susan (Rudbeckia hirta) | 18 – 21 | 65 – 70 | Yes |
| Bleeding heart (Dicentra spectabilis) | 4 – 12 | 40 – 55 | Yes |
| Boltonia (Boltonia spp.) | 18 – 21 | 65 – 70 | No |
| Borage (Borago officinalis) | 18 – 29 | 65 – 85 | No |
| Bugle flower (Ajuga spp.) | 10 – 15 | 50 – 60 | No |
| Bugloss (Anchusa capensis) | 18 – 21 | 65 – 70 | No |
| Butter daisy (Melampodium paludosum) |
18 – 21 | 65 – 70 | No |
| Butterfly flower (Schizanthus spp.) | 18 – 22 | 65 – 71 | No |
| Butterfly weed (Asclepias tuberosa) | 18 – 24 | 65 – 75 | Yes |
| Calendula (Calendula officinalis) | 18 – 21 | 65 – 70 | No |
| Californian poppy (Eschscholzia californica) | 12 – 21 | 55 – 70 | No |
| Candytuft (Iberis spp.) | 23 – 29 | 75 – 85 | No |
| Canterbury bells (Campanula medium) | 18 – 21 | 65 – 70 | Yes |
| Cape jewels (Nemesia strumosa) | 13 – 18 | 55 – 65 | No |
| Carnation (Dianthus spp.) | 15 – 21 | 60 – 70 | No |
| Catnip/catmint (Nepeta spp.) | 18 – 21 | 65 – 70 | No |
| Chamomile (Matricaria chamomilla) | 18 – 21 | 65 – 70 | Yes |
| Chilean bellflower (Nolana paradoxa) | 20 – 22 | 68 – 72 | No |
| Chinese aster (Callistephus chinensis) | 20 – 23 | 68 – 73 | No |
| Chinese forget-me-not (Cynoglossum amabile) | 18 – 20 | 65 – 68 | No |
| Chinese lantern (Physalis alkekengi) | 16 – 21 | 60 – 70 | No |
| Chrysanthemum (Chrysanthemum spp.) | 18 – 23 | 65 – 75 | No |
| Clematis (Clematis spp.) | 20 – 22 | 68 – 73 | Yes |
| Cliquefoil (Potentilla spp.) | 19-21 | 67-70 | No |
| Cohosh (Cimicifuga spp.) | 18 – 21 | 65 – 70 | No |
| Columbine (Aquilegia spp.) | 10 – 12 | 50 – 55 | Yes |
| Common rockrose (Helianthemum nummularium) | 21 – 24 | 70 – 75 | No |
| Common sneezeweed (Helenium autumnale) | 19 – 22 | 65 – 73 | No |
| Coral bell (Heuchera spp.) | 18 – 21 | 65 – 70 | No |
| Corncockle (Agrostemma githago) | 15 – 21 | 60 – 70 | No |
| Cornflower (Centaurea cyanus) | 15 – 21 | 60 – 70 | No |
| Cosmos (Cosmos bipinnatus) | 21 – 25 | 70 – 77 | No |
| Cup and saucer vine (Cobaea scandens) | 21 – 23 | 70 – 75 | No |
| Cupflower (Nierembergia spp.) | 21 – 23 | 70 – 75 | No |
| Cupid’s bow (Achimenes spp.) | 21 – 23 | 70 – 75 | No |
| Cupid’s dart (Catananche caerulea) | 20 – 23 | 68 – 75 | No |
| Cyclamen (Cyclamen spp.) | 18 – 20 | 65 – 68 | No |
| Dahlberg daisy (Dyssodia tenuiloba) | 18 – 21 | 65 – 70 | No |
| Dahlia (Dahlia spp.) | 21 – 23 | 70 – 75 | No |
| Delphinium (Delphinium elatum) | 15 – 20 | 59 – 68 | Yes |
| Echinacea (Echinacea spp.) | 18 – 21 | 65 – 70 | Yes |
| Edeiweiss (Leontopodium alpinum) | 18 – 21 | 65 – 70 | Yes |
| English daisy (Bellis perennis) | 18 – 21 | 65 – 70 | No |
| Evening primrose (Oenothera spp.) | 21 – 26 | 70 – 80 | No |
| Everlasting (Helichrysum bracteatum) | 21 – 24 | 70 – 75 | No |
| False sunflower (Heliopsis spp.) | 21 – 23 | 70 – 73 | No |
| Fan flower (Scaevola aemula) | 20 – 22 | 68 – 71 | No |
| Firecracker flower (Crossandra infundibuliformis) | 21 – 27 | 70 – 80 | No |
| Flax (Linum usitatissimum) | 18 – 21 | 65 – 70 | No |
| Fleabane (Erigeron spp.) | 18 – 21 | 65 – 70 | No |
| Floss flower (Ageratum houstonianum) | 24 – 29 | 75 – 85 | No |
| Forget-me-not (Myosotis spp.) | 18 – 21 | 65 – 70 | No |
| Foxglove (Digitalis spp.) | 15 – 18 | 60 – 65 | No |
| Garden heliotrope (Heliotropium spp.) | 18 – 21 | 65 – 70 | No |
| Gay feather (Liatris spp.) | 18 – 21 | 65 – 70 | Yes |
| Gazania (Gazania spp.) | 15 – 18 | 60 – 65 | No |
| Gerbera (Gerbera spp.) | 21 – 23 | 70 – 73 | No |
| Geum (Geum spp.) | 18 – 21 | 65 – 70 | No |
| Globeflower (Trollius spp.) | 18 – 21 | 65 – 70 | Yes |
| Glory of the snow (Chionodoxa spp.) | 10 – 15 | 50 – 59 | Yes |
| Gloxinia (Sinningia speciosa) | 19 – 21 | 66 – 70 | No |
| Goldencup (Hunnemannia fumariifolia) | 19 – 21 | 66 – 70 | No |
| Goldenrod (Solidago spp.) | 20 – 22 | 68 – 71 | Yes |
| Goldentuft (Aurinia saxatilis) | 15 – 21 | 59 – 70 | No |
| Hellebore (Helleborus spp.) | 18 – 21 | 65 – 70 | Yes |
| Hibiscus (Hibiscus spp.) | 21 – 26 | 70 – 75 | No |
| Hollyhock (Alcea rosea) | 15 – 21 | 60 – 70 | Yes |
| Iceland poppy (Papaver nudicaule) | 18 – 24 | 65 – 75 | Yes |
| Impatiens (Impatiens spp.) | 21 – 23 | 70 – 73 | No |
| Jacob’s ladder (Polemonium spp.) | 18 – 21 | 65 – 70 | No |
| Laceflower (Trachymene coerulea) | 18 – 21 | 65 – 70 | No |
| Ladys purse (Calceolaria spp.) | 21 – 23 | 70 – 73 | No |
| Larkspur (Consolida ambigua) | 10 – 12 | 50 – 55 | Yes |
| Lavender (Lavandula spp.) | 18 – 21 | 65 – 70 | No |
| Leopard plant (Ligularia spp.) | 18 – 21 | 65 – 70 | No |
| Linaria (Linaria spp.) | 12 – 18 | 55 – 65 | Yes |
| Lisianthus (Eustoma grandiflorum) | 22 – 23 | 72 – 73 | No |
| Livingstone daisy (Dorotheanthus bellidiformis) |
18 – 24 | 65 – 78 | No |
| Lobelia (Lobelia spp.) | 18 – 23 | 65 – 73 | No |
| Love-lies-bleeding (Amaranthus caudatus) | 20 – 28 | 68 – 82 | No |
| Lupine (Lupinus spp.) | 12 – 21 | 55 – 70 | Yes |
| Madagascar periwinkle (Catharanthus roseus) |
24 – 27 | 75 – 80 | No |
| Marigold (Tagetes spp.) | 21 – 23 | 70 – 73 | No |
| Marshmallow plant (Althaea officinalis) | 15 – 21 | 60 – 70 | Yes |
| Mexican creeping zinnia (Sanvitali procumbens) | 18 – 21 | 65 – 70 | No |
| Mignonette (Reseda odorata) | 12 – 14 | 53 – 57 | No |
| Monkey flowers (Mimulus spp.) | 15 – 21 | 60 – 70 | No |
| Monk’s hood (Aconitum spp.) | 12 – 15 | 55 – 60 | Yes |
| Morning glory (Convolvulus spp.) |
20 – 21 | 68 – 70 | No |
| Nasturtium (Tropaeolum majus) | 15 – 18 | 60 – 65 | No |
| Nemesia (Nemesia spp.) | 12 – 18 | 55 – 65 | No |
| Nemophila (Nemophila spp.) | 12 – 15 | 55 – 60 | No |
| Nigella (Nigella damascena) | 15 – 18 | 60 – 65 | No |
| Obedient plant (Physostegia virginiana) | 18 – 21 | 65 – 70 | No |
| Pansy (Viola tricolor var. hortensis) | 15 – 23 | 60 – 73 | No |
| Pearly everlasting (Anaphalis margaritacea) | 18 – 21 | 65 – 70 | No |
| Persian violet (Exacum affine) | 21 – 24 | 70 – 78 | No |
| Petunia (Petunia spp.) | 18 – 23 | 65 – 73 | No |
| Phlox (Phlox spp.) | 15 – 18 | 60 – 65 | No |
| Poppy (Papaver spp.) | 15 – 20 | 60 – 68 | Yes |
| Portulaca (Portulaca spp.) | 21 – 26 | 70 – 80 | No |
| Pride of Madeira (Echium candicans) | 15 – 20 | 60 – 68 | No |
| Primrose (Primula spp.) | 15 – 18 | 60 – 65 | Yes |
| Purple rock cress (Aubrieta deltoidea) | 18 – 21 | 65 – 70 | No |
| Queen Anne’s lace (Daucus carota) | 16 – 18 | 60 – 65 | No |
| Rock cress (Arabis spp.) | 18 – 21 | 65 – 70 | No |
| Rudbeckia (Rudbeckia spp.) | 21 – 23 | 70 – 73 | No |
| Salvia (Salvia officinalis) | 21 – 23 | 70 – 73 | No |
| Satin flower (Clarkia amoena) | 21 – 23 | 70 – 73 | No |
| Shooting star (Dodecatheon meadia) | 18 – 21 | 65 – 70 | Yes |
| Sea holly (Eryngium spp.) | 18 – 23 | 65 – 73 | Yes |
| Shasta daisy (Leucanthemum x superbum) | 18 – 21 | 65 – 70 | No |
| Snapdragon (Antirrhinum majus) | 18 – 23 | 65 – 73 | Yes |
| Snow-in-summer (Cerastium tomentosum) | 18 – 21 | 65 – 70 | No |
| Speedwell (Veronica spp.) | 18 – 24 | 65 – 75 | No |
| Spider flower (Cleome spinosa) | 21 – 23 | 70 – 73 | Yes |
| Statice (Limonium sinuatum) | 15 – 20 | 60 – 68 | No |
| Stock (Matthiola incana) | 15 – 18 | 60 – 65 | No |
| Stoke’s aster (Stokesia laevis) | 21 – 24 | 70 – 75 | No |
| Sunflower (Helianthus spp.) | 21 – 23 | 70 – 73 | No |
| Swan river daisy (Brachyscome iberidifolia) | 21 – 24 | 70 – 78 | No |
| Sweet pea (Lathyrus odoratus) | 12 – 18 | 55 – 65 | No |
| Trumpet flower (Incarvillea spp.) | 18 – 21 | 65 – 70 | No |
| Tweedia (Oxypetalum coeruleum) | 18 – 21 | 65 – 70 | No |
| Twinspur (Diascia spp.) | 15 – 18 | 60 – 65 | No |
| Verbena (Verbena spp.) | 18 – 23 | 65 – 73 | No |
| Viola (Viola spp.) | 18 – 23 | 65 – 73 | No |
| Virginian stock (Malcolmia maritima) | 18 – 23 | 65 – 73 | No |
| Wallflower (Erysimum cheiri, syn. Cheiranthus cheiri) | 15 – 18 | 60 – 65 | No |
| Wild indigo (Baptisia spp.) | 18 – 21 | 65 – 70 | No |
| Wishbone flower (Torenia fournieri) | 21 – 23 | 70 – 75 | No |
| Xeranthemum (Xeranthemum annuum) | 24-35 | 75 – 95 | No |
| Yarrow (Achillea spp.) | 18 – 21 | 65 – 70 | Yes |
| Yellow lotus (Nelumbo lutea) | 21 – 24 | 70 – 78 | No |
| Zinnia (Zinnia spp.) | 21 – 23 | 70 – 73 | No |
