Winter Sowing: Getting a Jump Start on Spring
Winter Sowing. Photo from University of New Hampshire
Does the thought of starting seeds indoors seem intimidating with the lights, trays, and threat of disease? Then skip that process and go to something much simpler: winter sowing. Winter sowing pioneered around 20 years ago in upstate New York but more and more gardeners are experimenting with it today.
Winter sowing is a simple, cost effective, and low maintenance way of starting seeds for the garden. The USDA defines it as “A propagation method used throughout the winter where temperate climate seeds are sown into protective vented containers and placed outdoors to foster a naturally timed, high percentage germination of climate tolerant seedlings.”
Why even entertain the thought of winter sowing? It is environmentally friendly, fun to experiment, plants can be started that are not readily available by other means, and it produces strong, healthy plants. If those are insufficient reasons, there is also no need for grow lights, constant watering or threat of damping off (dying) of tender seedlings, it eliminates the need for hardening off, and it provides natural stratification.
With winter sowing, containers remain outside all winter until the seedlings emerge in the spring. Those containers protect the seeds from animals and harsh weather. The cold weather helps break the dormancy of the seeds and they germinate at the appropriate time in the spring.
Not all seeds are appropriate for winter sowing. Look for seeds that use terms like reseeds, colonizes, self-sows, hardy seeds, withstand frost, need pre-chilling, need stratification, sow in late fall, or early spring while frost is still present. A good choice will always be native plants, perennials, some annuals, herbs, and some vegetables.
Timing is also important. In January and February, the native plants and other perennials (some of which need cold stratification) can be set out. This would include, but is not limited to: lobelia, butterfly weed, milkweed, liatris, coneflower, lavender, catmint, hellebores, Chinese lantern, native grasses, and vines. Cold weather vegetables and herbs can also be set out, including spinach, kale, Brussel sprouts, thyme, oregano, and parsley. Hardy annuals such as pansies, and ornamental kale can also go out.
Wait until March or April to set out tender annuals such as cosmos, zinnia, marigold, and tithonia. This would also be the time to put out vegetables and herbs such as bok choy, broccoli, snow peas, lettuce, basil, and cilantro.
Wait until April to begin more tender crops such as tomatoes, peppers, and eggplant.
To make a mini-green house container, use a clean gallon jug (other containers can be used, but must hold a minimum of four inches of soil). Make 4-6 holes in the bottom for drainage. Using a utility scissors or knife, carefully cut the jug just below the handle, leaving a hinge at the back so that the top portion will flip open while still attached. Discard the cap. Put a coffee filter or some newspaper in the bottom to keep the soil in and the slugs out. Add at least four inches of soil and moisten thoroughly.
Date and label the container with a permanent, UV resistant marker. As a back-up, put a marker inside the container as well. Plant each container with one type of plant at the depth recommended on the package. Tape the container shut with duct tape, all the way around.
Placing the container outside, choose a southeast location. Since the container is open, snow and rain will do the watering naturally. However, check periodically to see if it needs more. As the seedlings germinate and grow and the weather warms up, open the containers during the day and close them at night. Once the seedlings have their first true leaves and the weather is appropriate, they can be transplanted.
Enjoy the opportunity to experiment to grow plants in a new and exciting method.
Carol Shirk
Certified Master Gardener