It’s still a bit early for starting seeds indoors in the North, but I’ve been getting ready for it and setting out several winter-sowing containers. You’ll find a new how-to page on indoor seed starting on the header above, which gives the basics and a few tips based on good experiences (and bad ones) that I’ve had.
A couple of years ago, Northern Gardener ran an article by Michelle Mero Riedel on a seed starting technique called “winter sowing.” It was probably the most popular article we have run in the past five years. Basically, winter sowing is a way to start seeds outdoors.
Here’s how you do it: Collect a bunch of clear plastic containers. Michelle often uses clear 1 gallon milk jugs. I also like the larger plastic containers that salad greens come in. You clean the containers, poke holes in the bottom and top, and fill them with 2-4 inches of very moist seed-starting mixture. Then plant your seeds, tape up the containers tight, and put the containers outdoors. Tip: Be sure to write what you have planted in the container in a permanent marker inside the container. That’s all you do until spring.
Come spring, you’ll start to see little seedlings in the containers. At that point, you’ll want to poke more holes or open the containers up a bit during the day to keep the plants from over-heating. When the temperatures are warm enough, you just plant the seedlings in your garden or containers as you would any other plant starts.
Winter sowing works best for hardy perennials, I think, but some people use this method to start tomatoes and other plants. Since I have a meadow area that I plant out, I use winter sowing for additional plants for the meadow. This year, I started two kinds of lupines, a native coneflower (Rudbeckia laciniata) and tall rudbeckia (Rudbeckia hirta). These all do really well in winter sowing containers.
There’s an organization for winter sowers, as well, at this web site.