Get your hands dirty this winter by starting seeds outdoors using a practice called winter sowing. This method forgoes supplemental lighting and pricey seed-starting kits and lets nature’s rhythms coax seeds to sprout. Winter sowing is simple and yields sturdy seedlings that are ready to grow. If you have avoided starting seeds because you lack space or sunny windows, check out winter sowing.
To get started with winter sowing, you’ll need supplies you probably have around the house. Plastic containers, like milk jugs, 2-liter bottles or clear-lidded clamshell-type containers serve as a mini-greenhouse for the seeds. Use a box cutter or pen knife to cut around the middle of the container. Leave roughly a one-half inch section uncut to act as a hinge. What you’re doing is creating a hinged container that opens. Clamshell containers don’t require cutting.
Punch drainage holes in the bottom of the container. Use a lighter to heat the tip of the screwdriver to make punching through plastic easier. The container forms a mini-greenhouse for your seeds. Cut slits in the lid of the container to provide ventilation and prevent heat build-up. If your container has a lid (milk jug, 2-liter bottle), remove it.
Fill the container with 2 to 3 inches of soil. Winter sowing works best with a soil a mix that’s light and drains well. Bagged commercial peat moss and perlite mixes work great. Avoid mixes that feature water retention agents or moisture control properties. Wet soil thoroughly, place seeds on the surface, and add additional soil as needed to cover seeds. Pat the soil lightly to ensure good seed to soil contact, and close your container. Use a piece of duct tape to hold the container closed. Be sure to label containers with planting date and seed.
Commonly grown in North America and Eastern Asia, Japanese yew is an excellent fit for porches all year round since it's drought tolerant and thrives in both full and partial sun settings. Known to survive exceptionally harsh winters, the Japanese yew is popularly used as groundcover; however, when grown as a tree, it can reach more than 50 feet in height.
Potted Blue Spruce
The Colorado blue spruce is one of the most iconic evergreens associated with holiday decorating. Commonly raised as Christmas trees, it must have full sunlight to thrive and also requires a great deal of watering. If used as a potted accent, add a hole for proper drainage. It's also recommended to lay a sponge directly over the drainage hole to help hold moisture.
Similar to boxwood hedge, potted cypress works well as topiary. For the best growth possible, place potted cypress in an area that receives morning sun and afternoon shade. As far as watering is concerned, cypress can rot easily if oversaturated, so it's best to water in the morning to allow for proper evaporation before the sun fades.
Known for its golden-yellow foliage, thread-branch cypress can add great texture to an outdoor space during the winter. In addition to its unique coloring, this sun-loving evergreen takes an interesting shape as its thread-like needles "weep" downward. When planted in the ground, thread-branch cypress can grow as big as six-by-eight-feet tall. Whether it's being used in a container or planted in the ground, this cypress will need full sun to thrive.
Winter Gem Boxwood
Perfectly fit for small hedges when planted in multiples, Winter Gem boxwood also works well potted in planters. During the winter, this evergreen will take on a golden bronze coloring, then change back to bright green in the spring. Winter Gem boxwood thrives in both partial and full sun settings.
Ligustrum is an evergreen native to Japan which is commonly grown for ornamental use in California, Texas and throughout the Southeastern United States. Popular with homeowners in urban and rural settings, Ligustrum thrives in full sun and partial shade and adapts to different types of soil.
A perfect fit for topiary and container gardening, English boxwood is a small evergreen shrub known for slow growth and yellow-green coloring on its leaves. At full maturity, this shrub will reach two feet in width and height. Like most shrubs, it simply requires watering twice a week and full sun exposure.
Wheeler's Dwarf Japanese Mock Orange
Best used as groundcover, Wheeler's Dwarf Japanese Mock Orange is known for producing small scented flowers with orange coloring. When grown in partial to full sun, the groundcover can reach three feet in height and five feet in width.
Set your planted containers outdoors in a spot that’s protected from winds, but receives sunlight, snow and rain. You might want to place your containers into a greenhouse flat or plastic tub to ensure your little greenhouses stay upright. Make sure the tray has drainage holes—if not, create them.
Winter sowing relies on cycles of freezing and thawing to loosen seed coats and prepare seeds to germinate. When spring first arrives with sunny days but still freezing nights, you’ll start spotting seedlings. At this point, on a day when temperatures are above freezing, open containers and check soil dryness. Water if needed, using a gentle spray. Replace lids.
As spring settles in and air steadily warms, open containers during the day for a few hours to start hardening off seedlings. Continue to tape containers closed at night to protect seedlings from chilly air. Eventually as nights warm, you can leave container lids off permanently. Plant seedlings into the garden or containers on a cloudy day to reduce transplant shock.
Winter sowing works with perennials, hardy annuals, vegetables, herbs and tender annuals. You just have to get the timing right. Sow seeds for plants that are hardy in your zone—including hardy annuals and vegetables—anytime during winter. Tender plants—including annuals and vegetables—should be sown closer to spring (March or April in Zone 5). Heat-loving vegetables, like tomatoes, should be planted a month later.