Sauk County Gardener: Winter Sowing
"Every gardener knows that under the cloak of winter lies a miracle ... a seed waiting to sprout, a bulb opening to the light, a bud straining to unfurl. And the anticipation nurtures our dream." - Barbara Winkler
Even though everything is covered in snow, I’m already getting antsy to work in my gardens. If you’re feeling like me, there’s an easy to get your hands in the soil and get a head start on your garden. I’m talking about winter sowing. If you’ve never tried winter sowing, you should really give it a try. You can do a little or a lot; it really depends on if you have or can find a good supply of plastic jugs or containers that are transparent or semi-clear.
Winter-sowing is basically creating little greenhouses for seeds that need to be stratified or chilled to germinate. It’s a great way save money by starting plants from seed and recycling those plastic jugs and containers instead of sending them directly to the landfill. It’s also a great project to do with the kiddos. For winter sowing, you’ll need plastic containers or jugs that are able to hold around four inches of soil and tops that are able to allow sunlight in. Other supplies needed include potting soil, a sharp knife or scissor, clear packing or duct tape, and of course, seeds. You’ll also want something to label your containers – I recommend either writing on the container directly or on a plastic plant label – use a pencil, marker, or paint pen that won’t fade in the sunlight.
Before you get started, let’s talk seeds. Seeds that need a chilling period or require stratification or scarification are a great choice. Stratification is a technique that mimics the winter conditions (i.e. long periods of cold temperatures) so the seeds will know when to germinate. Scarification cracks or weakens a seed’s tough shell. Read the seed packets and look for these two words or terms such as self-sow, direct-sow early, or pre-chill. Here are a few perennials that fit this bill: Coneflower, black-eyed or brown-eyed Susan, foxglove, blanket flower, blazing star, butterfly weed, milkweed, speedwell, tickseed, bee balm, and delphinium. Some hardy annuals to consider include morning glory, Mexican sunflower, cosmos, Canterbury bells, cornflower, larkspur, China aster, calendula, sweet peas, snapdragon, and lupine. You can even start some cool-season vegetables this way such as lettuce, bok choy, and plants in the Brassicaceae family like kale, broccoli, or cauliflower. Sage, oregano, and dill are a few herbs that can be started via winter sowing. Here’s a general timeframe you can follow for our area: January and February – perennials that need cold stratification, March – hardy annuals and cool-season crops.
Once you have all your supplies, you’re ready to plant. If you’re using a milk jug or two-liter bottle, cut it in half (so there five to six inches to put soil in the bottom half), leaving a hinge to keep the top half attached to the bottom. Make drain holes in the bottom and air and moisture vent holes on the top half of the container lid. Fill the container with around four inches of potting soil (don’t use garden soil – it’s too heavy), and then plant your seeds. Follow the directions on the seed packet as to the recommended depth. If you don’t have a seed packet to reference, plant the seed at a depth of two to three times its width. Really small seeds probably won’t need to be covered at all with soil. Label the container using a plant label or write directly on the container. Water gently (unless your soil is already moist) and then cover. If need be, tape the lid down with the packing or duct tape so it doesn’t get accidently blown or knocked off. Then place your containers outside in a sunny location where they are protected from the wind and animals, but still exposed to snow and rain. Then just sit back and let the containers get snowed and rain on until it starts warming up.
As it gets warmer, check on your containers for germination from time to time. Once the seedlings start growing, add more holes to provide additional air circulation. They may need additional water as well, so they don’t dry out. Eventually, you can open the top completely during the day, so your seedlings don’t get too warm. Once the danger of frost is past, completely remove the lid. When your plants reach the top of your container and have a good sturdy root system (easy to see if you use transparent containers), you can divide and transplant them into individual pots or directly in the garden.
Try winter sowing to get a head start on your summer garden and a lot of plants for the price of a seed packet. If you need inspiration, check out the seed packets showing up in stores right now. For additional information on winter sowing, visit https://extension.psu.edu/successful-winter-seed-sowing.
Quick reminder: check on your stored dahlias, glads, cannas or any other tender bulbs to get rid of any bad ones so they don’t spoil the rest.
Remember to contact Extension Sauk County if you have any gardening questions. Please send an email to haley.weisert@saukcountywi.gov or call the University of Wisconsin Madison Division of Extension Sauk County office at 608-355-3250.
Jeannie Manis is president of the Sauk County Master Gardeners Association.
