Planting seeds in winter, referred to as winter sowing, prepares seeds to germinate in the spring at the appropriate time. The process relies on natural cycles of freezing and thawing to activate germination. When planted in winter and placed outside, the seeds respond to the sun's warmth in early spring, germinating naturally once the danger of cold weather has passed. Plants emerge and thrive (much as volunteer plants appear in the garden) when growing conditions are right.
Choose seeds from native plants in your area or those labeled as requiring pre-chilling. Perennials or annuals that self-seed are also good choices. Browse seed catalogs and review the germination charts to determine which seeds require pre-chilling.
Select flats or containers with clear plastic lids. Recycled deli containers make excellent flats for winter sowing, functioning as mini-greenhouses.
Punch drainage holes in the bottom of the containers with a nail or other sharp object.
Fill the trays with seed starter and plant seeds to their recommended depths recommended on the back of the seed packets.
Water to moisten soil, then close the lid. Seal with a section of packing tape to prevent the top from coming loose from exposure to the elements.
Place the seed tray in a sheltered area of your yard, out of strong winter winds, where it can receive daily sunlight. An old picnic table or bench provides stability and support for your seedlings.
Check seedlings in spring when snow melts and the weather warms. Punch holes in the cover for air circulation once seedlings emerge. Remove the cover when seedlings are 2 inches high.
Plant in the desired location once seedlings are 4 to 6 inches high.