December in our region means late dawns and early sunsets. Leaving work for home, we find ourselves switching on the high beams to avoid deer—at 4:30 in the afternoon. Weeks go by in a blur of grey days and we long for the chlorophyll-saturated landscape of summer.
Normally, December holidays keep us busy enough to disregard the bleak, frozen fields and dim skies. But a pandemic has put a damper on the usual festivities this year, so we might need to find new ways to celebrate, new rituals to usher in the light.
May we suggest sowing flowers?
Don’t worry, we haven’t lost our marbles just yet. Sowing flowers in winter is actually nothing new.
Many flowers enjoy a period of cold stratification in order to germinate come springtime. And of the flowers that like a period of cold, wet weather, some of these prefer to be direct-sown (like Poppies, Milkweed, and Butterfly Weed). Others don’t require direct sowing, but it sure makes things easier (no need for growing mediums, fancy equipment, or space in the refrigerator).
Mainly, you’ll need a patch of well-drained, weed-free soil and plant markers to remind you to keep a lookout for seedlings come springtime. Over-sow by about 20% if you want to account for run-off and nibbling critters. Water once and let seasonal precipitation and low temps do their magic until spring.
Here are some of our favorite varieties to winter sow.
Milkweed (Asclepias syriaca) and Butterfly Weed (Asclepias tuberosa) both need cold stratification in order to germinate, making winter the perfect time to sow a butterfly sanctuary. Monarchs and other butterflies rely on Asclepias for nourishment and habitat. Learn more about sowing Milkweed here.
Poppies are extraordinarily beautiful but you will be hard-pressed to find poppy seedlings at your local nursery in spring. This is because most poppies do not transplant well and prefer to be direct-sown into the garden. The good news is that poppies are very easy to grow, even in poorer soils. Read more about growing poppies here.
Self-sowing annuals like Johnny Jump-Ups, Chamomile, and Spider Flower will readily tough out the cold. If the winter is not overly harsh, Calendula, Borage, and Marigolds will also do quite well.
Many flowering perennials require an extended period of cold in order to germinate. Campfire Rudbeckia, Echinacea, Columbine, and Yarrow can all be winter-sown. Try Blazing Star or Anise Hyssop for vertical interest.
Biennial Forget Me-Nots and Tina James’ Evening Primrose can be sown anytime between fall and late winter. Thin the seedlings in spring and give them plenty of room to become established over the first growing season. The following year, they will flower and begin the process of self-sowing in place so that you will see them year after year. Keep your biennial patch free from over-competitive weeds.
If you are not exactly sure where you want your winter-sown plants to grow, or otherwise prefer a little more control over the germination process, you can sow your seeds in plastic containers and leave them outside. Use Trudi Geissle Davidoff’s technique of sowing cold-hardy and semi-cold-hardy seeds into light-permeable plastic containers and leaving them, partially covered, outdoors (find details on her website wintersown.org). This approach allows added protection from really low temps, run-off, and critters and helps you keep track of what you’ve sown. Find her guide here.
The new Sow in the Snow Boxed Seed Collection is a good place to start with winter sowing; it includes Bloomsdale Spinach, Mother of Pearl Poppy Mix, German Chamomile, Mache, and Butterfly Weed. These varieties also do well in tight spaces.
And finally, if you are interested in growing vines, sow Heavenly Morning Glory or Moon Flower, members of the Ipomoea family that use winter’s fluctuations in moisture and cold to break down the hard seed coat typical of these seeds. Another option is Balloon Vine, or Heartseed, known to self-sow in the garden but not considered an invasive in our region; Balloon vine will readily tough out a mild Northeastern winter.
On December 21st, the Northern Hemisphere will begin to inch its way back to a sunward tilt (at 5:02 a.m. EST, but who’s counting?). We think the Winter Solstice makes a good day for a new winter ritual, don’t you? Celebrate the return of light by sowing a mini meadow like Eastern Pollinator Mix or Shady Meadow Mix. The result? A field of happy flowers smiling back at you next year.