Here is The Garden Geeks list of seeds we have successfully hot capped (also known as winter sown) in previous years. The zone in parenthesis is the zone in which a member has successfully sown the seed.
This is a work in progress. E-mail Us if you can add more!!
Botanical Names Starting with A
with links to their Guide Pages
Achillea millefolium - Yarrow (Zone 4)
commercial - sprinkle seeds on surface. Do not cover
Achillea ptarmica - Sneezeweed (Zone 4)
collected - surface sow seeds, do not cover
Aconitum lycoctonum subsp. neapolitanum (Zone 4)
collected - surface sow, do not cover. These seeds can take 5 days to several months to germinate.
Aconitum napellus - Monkshood (Zone 4)
collected - surface sow, do not cover.
Adenophora stricta - Ladybells (Zone 4)
collected - surface sow, germination can take one to three months.
Agastache cana - Wild Hyssop (Zone 4)
collected - barely cover with soil. Germinates quickly when weather hits 70 degrees.
Agastache foeniculum - Anise Hyssop (Zone 4, 5, 6, 7, 8)
collected and commercial - barely cover seeds with soil. Can tale as much as 1 to 3 months after temps reach 55ºF. Plants grown from seed will bloom second year.
Ageratina altissima - White Snakeroot (Zone 4)
collected - barely cover seed with soil, the fresher the seed, the better the germination.
Alchemilla alpina - Mountain Lady's Mantle (Zone 4)
colected - just cover seeds, germination can take up to a month once temps rise above 55.
Amsonia tabernaemontana - Eastern Bluestar (Zone 4)
collected - barely cover with soil, germination can take about a month after temps warm to about 60 degrees.
Anchusa azurea - Italian Bugloss (Zone 4)
collected - barely cover seeds with soil, fast germination after temps reach 70 degrees.
Anemone sylvestris - Snowdrop Anemone (Zone 4)
collected - difficult to germinate. used jars. took almost 3 months after temps reached 70 degrees before germination.
Angelica archangelica - Angelica (Zone 4)
collected - took 15 days after temps reached 70.
Antirrhinum majus - Snapdragon (Zone 4)
collected - sprinkle on the surface, do not cover with soil.
Aquilegia canadensis - Wild Columbine (Zone 4)
collected - surface sow
Aquilegia vulgaris - European Columbine (Zone 4)
collected
Arabis procurrens - Rockcress (Zone 4)
commercial - surface sow
Arisaema triphyllum - Jack In The Pulpit (Zone 4)
collected - barely cover with soil.
Armeria maritima - Sea Thrift (Zone 4)
commercial - barely cover seeds with soil.
Aruncus dioicus - Goat's Beard (Zone 4)
collected - sprinkle seeds on surface of soil. Do not cover seeds with soil.
Asclepias incarnata - Swamp Milkweed (Zone 4)
collected - barely cover seed with soil.
Asclepias speciosa - Showy Milkweed (Zone 4)
collected - barely cover with soil.
Asclepias tuberosa - Butterfly Weed (Zone 4)
collected - barely cover seeds with soil.
Aster pilosus - Downy Aster (Zone 4)
collected - barely cover seeds with soil.
Aster sericeus - Silky Aster (Zone 4)
collected - barely cover seeds with soil.
Aurinia saxatilis - Basket of Gold (Zone 4)
commercial - surface sow, do not cover seeds with soil. Germination will be fast once temps reach 60.
Botanical Names Starting with B
with links to their Guide Pages
Baptisia alba - White False Indigo (Zone 4)
collected - cover with about 1/4 inch of soil
Baptisia australis - Blue False Indigo (Zone 4)
collected - cover with about 1/4 of inch of soil.
Baptisia tinctoria - Wild Indigo (Zone 4)
collected - cover with about 1/4 inch of soil
Belamcanda chinensis - Blackberry Lily (Zone 4)
collected - barely cover seeds with soil
Bellis perennis - English Daisy (Zone 4)
commercial - do not cover seed with soil. germination is quick after temps reach about 70 degrees
Boltonia asteroides - Boltonia (Zone 4)
collected - barely cover seeds with soil.
Borago officinalis - Borage (Zone 4)
collected - self sows easily.
Brassica rapa var. chinensis - Bok Choy (Zone 4)
collected
Brunnera macrophylla - Siberian Bugloss (Zone 4)
collected - barely cover seeds with soil. This seed needs to be chilled for at least a month before germination.
Botanical Names Starting with C
with links to their Guide Pages
Callirhoe involucrata - Wine Cups (Zone 4)
collected - sow seeds on top of soil...seeds have to be chilled for at least 4 months before they will germinate.
Callistephus chinensis - China Aster (Zone 4)
commercial - barely cover. These seeds will not germinate if not chilled for several weeks first.
Campanula carpatica - Carpathian Harebell (Zone 4)
collected - sprinkle on the surface, do not cover with soil. keep out of strong hot sunlight.
Centaurea cyanus - Bachelor's Button (Zone 4, 5, 6, 7, 8)
commercial - barley cover, seeds sown in a dark place germinate better.
Clarkia amoena - Farewell-to-Spring (Zone 4, 5, 6, 7)
collected - do not cover seed with soil, best germinating results if you start seed about 2 months before last frost. Stronger plants from seeds sown outside.
Clintonia andrewsiana - Andrew's Bead-Lily (Zone 4)
collected - barely cover seed with soil. This seed can take 2 months to germinate once temps reach about 60 degrees.
Collinsia bicolor - Chinese Houses (Zone 4)
collected - cover with a quarter of an inch soil.
Botanical Names Starting with D
with links to their Guide Pages
Delphinium grandiflorum - Chinese Delphinium (Zone 4)
collected - barely cover seeds. Seeds need to be chilled for at least two weeks. They will germinate within 2-3 weeks once temp reaches about 60.
Dicentra spectabilis - Bleeding Heart (Zone 4)
collected - barely cover seed. This seed needs to be stratified.
Botanical Names Starting with G
with links to their Guide Pages
Gaillardia x grandiflora - Blanket Flower (Zone 4,5,6,7,8)
commercial - don't cover seeds with soil. They need light to germinate. Will germinate quickly when temps reach about 70 degrees.
Gentiana andrewsii - Bottle Gentian (Zone 4)
collected - barely cover seeds with soil.
Geranium sanguineum - Bloody Cranesbill (Zone 4,5,6)
collected - barely cover seeds with soil. Germination can take up to 2 months after temps reach 70 degrees.
Geum montanum - Alpine Avens (Zone 4)
Collected - barely cover seeds with soil. Germination can take up to 1 months after temps reach 65ºF.
Gillenia trifoliata - Bowman's Root (Zone 4)
collected - cover seeds with about a quarter of an inch soil.
Gypsophila elegans - Baby's Breath (Zone 4)
commercial - Barely cover with soil. Germination within 3 weeks after temps reach 70 degrees.
Botanical Names Starting with I
with links to their Guide Pages
Ipomoea purpurea - Morning Glory 'Sunrise Serenade' (Zone 4)
collected and commercial - about 1/8" below the surface. Bottle covered in snow. 2 years in a row complete success.
Botanical Names Starting with L
with links to their Guide Pages
Ligularia dentata - Bigleaf Ligularia (Zone 4, 5)
collected - Plant seeds on the surface. Don't cover with soil. Takes up to a month when temps reach 60 degrees.
Linum perenne - Blue Flax (Zone 4,5,6,7)
collected and commercial - cover with 1/8 of an inch of soil, germination in about a month when temps reach 65 degrees.
Botanical Names Starting with M
with links to their Guide Pages
Matthiola longipetala - Night-scented Stock (Zone 4)
collected - do not cover seeds with soil. Seeds germinate within 25 days after temps hit 70 degrees.
Moluccella laevis - Bells of Ireland (Zone 4)
collected - Don't cover seed with soil. Germinates in about a month once temps reach 60 degrees.
Botanical Names Starting with P
with links to their Guide Pages
Papaver alpinum - Alpine Poppy (Zone 4)
collected - barely cover seeds with soil (seeds need darkness). Germination in about 20 days after temps reach 70 degrees.
Papaver burseri - Alpine Poppy (Zone 4) collected - barely cover seeds with soil (seeds need darkness). Germination in about 20 days after temps reach 70 degrees.
Penstemon barbatus - Beardtongue (Zone 4)
commercial - Do not cover seeds with soil. Germination is within a month of temps reaching 65 degrees.
Phacelia campanularia - California Bluebells (Zone 4)
collected - Cover seeds with about a quarter of an inch of soil. Germination will be within a month of temps reaching 65 degrees.
Platycodon grandiflorus - Balloon Flower (Zone 4, 5, 6, 7, 8)
commercial and collected - Don't cover seeds with soil. Germination within a month of temps reaching 70 degrees. Seeds need light for germination.
Potentilla fruticosa - Shrubby Cinquefoil (Zone 4)
collected - Barely cover seeds with soil. Germination within a month of temps reaching 65 degrees.
Pulsatilla alpina subsp. apiifolia - Alpine Pasque-flower (Zone 4)
collected - This one is difficult to germinate. Can take up to 5 months after temps reach 60 degrees. Barely cover seeds with soil.
Pulsatilla hirsutissima - American Pasque Flower (Zone 4)
collected - This one is difficult to germinate. Can take up to 5 months after temps reach 60 degrees. Barely cover seeds with soil.
Botanical Names Starting with R
with links to their Guide Pages
Rudbeckia hirta - Black Eyed Susan (Zone 4, 5, 6, 7, 8)
collected- Don't cover seeds with soil. Germination within a month of temps reaching 70 degrees.
Botanical Names Starting with S
with links to their Guide Pages
Sanguinaria canadensis - Bloodroot (Zone 4)
collected - No notes given in journal, just said that they did sow in the winter.
Silene coronaria - Rose Campion (Zone 4,5,6,7)
collected - sow seeds on surface of soil. germination can take up to 30 days after temps reach 70 degrees. Seeds need light to germinate.
Botanical Names Starting with T
with links to their Guide Pages
Tagetes erecta - African Marigold (Zone 4, 8)
commercial - Barely cover seeds with soil, germination can take up to 2 weeks after temps reach 70 degrees.
Thermopsis villosa - Carolina Lupine (Zone 4)
collected - Barely cover seeds with soil, germination within a month of temps hitting 70 degrees.
Thunbergia alata - Black-Eyed Susan Vine (Zone 4)
collected - barely cover seeds with soil, germination within a month of temps reaching 65 degrees. Appears to germinate best with fresh seeds.
Botanical Names Starting with W
with links to their Guide Pages
Wisteria sinensis - Chinese Wisteria (Zone 4)
collected - cover seed with about an inch of soil, germination in about a month after temps reach 60 degrees.