Start seeds outdoors this winter and welcome spring with seedlings of your own. Winter sowing uses recycled containers, natural daylight, and outdoor temperatures instead of indoor grow lights. It is especially useful for many hardy flowers and perennials that require seed stratification. Natural stratification can provide increased germination rates over refrigerator stratification when conditions are right. Natural Stratification can also be tried when refrigerator stratification did not provide ideal results.
Shop Winter Sowing Seeds | Learn about seed stratification
What is winter sowing?
Seeds are planted in containers that remain outdoors. For species that need it, exposure to cold and moisture helps release dormancy. Other hardy species can grow this way without requiring a cold treatment. Seeds sprout when their particular temperature and light requirements are met.
Winter sowing is not a substitute for every seed treatment. Some seeds also need scarification, soaking, or a warm period. Always follow the packet and species-specific instructions.
When should you start?
In Maryland, late November through January is a useful starting window for seeds needing a substantial cold-moist period. Match your sowing date to the treatment length on the packet and your local winter. In warmer climates, outdoor conditions may not provide enough chilling.
Hardy annuals and cool-season vegetables can be started later. Tomatoes and other frost-sensitive crops need different timing and protection; do not treat them like cold-hardy perennials. A warm container by day can still freeze at night.
What you need
- A clean, translucent gallon jug (milk jugs work great) or clear container with room for roots and seedlings
- Fine-textured seed-starting mix
- Seeds, water, waterproof tape, and durable labels
- A tool for drainage holes and an adult to cut containers safely
Prepare and sow
- Make drainage and ventilation openings. Cut a jug around its middle, leaving a hinge under the handle. Make several bottom drainage holes. Leave the screw cap off; other lids need ventilation.
- Add moist mix. Use about 3–4 inches of growing medium. Let excess water drain. Avoid garden soil and standing water.
- Sow at the correct depth. Space seeds rather than emptying a packet into one small area. Seeds needing light should stay on the surface; cover others only as directed.
- Label twice. Put the plant name and sowing date on the container and an inside label.
- Close the cut seam. Tape the hinged top back into position while keeping the ventilation opening clear.
Where to put containers
Choose a stable outdoor spot with daylight and protection from being knocked over. Containers should receive outdoor weather, not sit in a heated room. Secure them against wind and animals. Reassess sun exposure as spring approaches: enclosed containers can overheat.
Winter and spring care
Check moisture periodically, especially after dry or windy weather. Rain and snow may help, but do not assume enough water reaches the mix. Water gently when needed and let it drain; keep the medium damp rather than saturated.
Once seedlings emerge, monitor containers more often. Increase ventilation and gradually open the tops as weather allows. Protect young growth from damaging freezes according to the species. Closed jugs are not frost-proof.
Seedlings raised under covers still benefit from gradual exposure to stronger sun, wind, and open air. Transplant when they have true leaves and a developed root system, and outdoor conditions suit that plant. Water after planting.
If nothing sprouts
Different species emerge at different times. Check treatment requirements, sowing depth, moisture, and drainage before giving up. Some seeds need another seasonal cycle; a quiet container is not automatically a failure.
Choose your seeds
Browse our Winter Sowing Seeds collection and read each listing before choosing. Pick plants suited to your garden's light, moisture, and space. Start with a few labeled varieties so you can learn what works in your location.
Seed shipping: $2 for unlimited seed packets with untracked shipping.