Outdoor Winter Gardening
A Gardener’s Cure to Winter Blues
Across Montana
Written and Photographed by Amy Grisak
There’s a foot of snow on the ground and the temperature is in the single digits but many of us are itching to plant something! Seeding annuals, perennials, and cool-season vegetables allows us to satisfy the need to plant something, while gaining time in the spring allowing for an earlier harvest. While starting seeds indoors is a right of passage for many gardeners, winter sowing is an easy way to gain a jump on the season with minimal effort.
For decades I’ve started many of my vegetables, flowers, and herbs in the house, seeding peppers, basil, and onions in late January, and progressively adding to the list until March.
The biggest challenge with this traditional way of starting seeds indoors is light and space. Providing the 10 hours of light they need to grow well can be difficult though I’ve managed to make it work by moving plants from window to window, and thankfully LED lights are portable and terrific for seed starting.
Sowing indoors also takes up a considerable amount of space inside the house, at least for a while, especially if “one little container” turns into 20 flats of seedlings like it often does for me. I have had 20 flats of seedlings covering the table and countertops until I could safely move them to my small greenhouse.
Right now the ground is frozen and as hard as a rock, but for winter sowing we plant the seeds in containers that are set outdoors. The thought is that there are certain plants that need stratification, known as a chill period, for them to germinate properly.
There are also some seeds that overwinter just fine, and these will germinate on their own time schedule. Think about it, how many times have you had lettuce or spinach reseed without any help from you? That’s how this works, but in a more controlled setting.
As for timing, most northern gardeners wait until after the New Year and seed outdoors from February to the first part of March. So, whenever you feel you need to plant something, grab your containers, potting soil, and seeds and go for it.
What to Plant
Any seeds that you collected in the fall can go into containers now. I am starting a couple of new-to-me penstemon varieties sent to me by the American Penstemon Society, along with other perennials such as Echinacea and delphiniums.
Perennials: Winter sowing is an excellent method for many species, particularly with native varieties. Most, if not all, of these require a certain amount of time in cold conditions, and winter sowing mimics these natural conditions.
Flowers: Look for varieties that say “self-sowing.” I love cosmos, zinnias, bachelor’s buttons, and marigolds for this method. These will all reseed in the garden, but you’ll have flowers sooner if you plant them in containers now.
Vegetables: Cool season crops such as lettuce, spinach and other greens are a top choice. So are cabbage, broccoli, and others in the Brassica family.
(Tomatoes, peppers, and squash don’t do well with this method because they like hot temperatures and are far more cold sensitive. Even though they might germinate with nicer weather and sunny days inside of the outdoor containers, a spring frost will kill them.)
Containers
Gallon Milk jugs: One of the best aspects of winter sowing is you can use recycled plastic containers of all sorts. Cut them in half, leaving a piece of plastic hanging on like a hinge, or cut a window in the side to vent the jug when the weather improves.
Clear Plastic Containers: Reuse the containers from the store that mixed greens and fruit come in. Even the ones for rotisserie chickens will do the trick! It’s terrific to be able to use these again instead of just throwing them in the trash.
Ziplock Bags or Clear Totes. Gallon-sized Ziplock bags are good for seeding a large amount of a specific plant. When using bags, they can be set in a large tub to keep them together, or a nifty method is to hang them from dowels.
Drill or cut holes in the bottom to allow excess water to drain through. If you’re using baggies, snip three or four holes in the bottoms.
Planting the Seeds
Fill the containers with two to four inches of potting soil, set it in the sink or a bowl, and water until it drains out the bottom.
Sprinkle the seeds on top of the potting soil. Be generous in this regard because you will most likely not have 100% germination. Plus, you’re going to transplant the seedlings to the garden when the time is right so they can be a little thick on those instances when all the conditions work out right. After seeding, scatter a thin layer of potting soil on top of the seeds.
Close the containers, leaving just a slight opening for ventilation. For the milk jugs, even if you tape the seam, leave a small space untaped. Later, when the weather warms, you’ll be able to remove the lid to aid air flow. If it’s a salad container, cut a small square Use a waterproof marker to write what you planted and the date somewhere on the container.
Place the seeded containers in a sunny spot that is sheltered from the wind. You don’t want to watch your milk jugs tumbling across the yard! It’s fine if they are buried with snow and the thermometer drops well below zero. There is also no need to water. Just let Mother Nature take care of things for a while.
When the end of winter finally rolls around with longer days and warmer weather, the seeds follow nature’s cues and they germinate in their protected containers. During this time, you’ll want to watch the weather to crack or remove the lids during warm, sunny days so the tiny plants don’t cook, but for the most part, they don’t require much care until the soil is warm enough for you to plant the transplants in the garden.
If you want to experience the easy way to start a few of your flowers, herbs, or vegetables, grab that milk jug and try your hand at winter sowing. I have a feeling it’ll become a regular part of your gardening practice.
