What to Winter Sow by Zone
The best seeds to winter sow in milk jugs: perennials that need cold, hardy annual flowers, cool-season vegetables and herbs, and tender crops, plus what...
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What to Winter Sow by Zone
The best winter-sow seeds are hardy in your zone or tolerate cold: perennials and natives that need a cold spell, self-sowing flowers, and cool-season vegetables. Tender crops like tomatoes work too if you sow them last.
Seed packets give clues. Look for "self-sows," "hardy annual," "sow outdoors in fall or early spring," "needs cold stratification," or "seedlings tolerate frost."
Pick crops and get dates on the Winter Sowing Desk.
Perennials and Natives That Need Cold
Sow first, 20 to 10 weeks before last frost.
- Coneflower: germinates more evenly after cold
- Black-eyed Susan: cold raises germination
- Columbine: needs about 3 to 4 weeks of cold
- Lupine: nick or soak the hard seed first
- Milkweed: needs about 30 days of cold, moist weather
- Lavender: slow and uneven; cold helps
Hardy Annual Flowers and Self-Sowers
Sow 14 to 8 weeks before last frost.
- Poppy, larkspur, bachelor's button
- Snapdragon, sweet pea, pansy
- Hollyhock, dianthus
Cool-Season Vegetables and Herbs
Sow 10 to 4 weeks before last frost.
- Greens: lettuce, spinach, kale
- Brassicas: broccoli, cabbage
- Alliums: onion, leek, chives
- Herbs: parsley, dill, cilantro
Tender Crops
Sow last, 6 to 3 weeks before last frost. Plant out after last frost.
Peppers are slow in a cool jug. In zones 3 to 5, indoor starts under lights are more reliable. See the seed-start calendar.
What to Skip
- Squash, pumpkin, cucumber, melon, beans, corn, okra: fast and frost-tender, and they dislike transplanting. Direct sow after last frost.
- Carrot, parsnip, radish: roots fork or stall when moved. Direct sow.
- Peas: direct sow as soon as the soil can be worked.
By Zone
- Zones 3 to 7: everything above works. Perennials get a full cold spell.
- Zones 8 and 9: hardy flowers and cool crops work well. For seed that needs a long cold spell, sow in early December or fridge-stratify first.
- Zone 10 and warmer: jugs do not get cold enough. Direct sow cool crops in fall and winter.
Check that old packets still sprout on the Seed Viability Check before you fill jugs, then plan dates on the Winter Sowing Desk.
Sources: Penn State Extension, Starting Seeds in Winter; South Dakota State University Extension, Winter Sowing in the Northern Great Plains; Ohio State University Extension, Licking County Master Gardeners, Winter Seed Sowing.