A few years ago I was browsing the web site, GardenWeb.com, and came across their forum on winter seed sowing. I have always started seeds for my vegetable garden and so I checked it out. The concept was intriguing; so even though I have a light table set-up in my basement, I gave it a try. The process involves planting seeds in plastic containers and setting them outside in the middle of winter. Photos on the web site showed backyards and patios filled with milk jugs, plastic lettuce containers, and other recycled containers covered with snow. My first thought was that the seed would rot before the winter was over, but it is basically the same process Mother Nature uses. When seeds leftover from a rotting tomato or flower fall to the ground at the end of summer, they winter over and germinate the following spring.
The system has several advantages. You‘re not taking up space in your house or window sills and the snow and rain provide moisture so you don’t have to water as often. In fact, some growers report that they never have to do any watering until well into spring. The seedlings also prove to be stronger than those grown under lights or inside and it eliminates the problem of damping off. The most readily available container, and the one that I chose, is a gallon milk jug. After washing and drying it, cut the jug horizontally about 4” from the bottom. Don’t make the cut all the way around; leave about a 2” piece just below the handle intact to act as a hinge. Throw the cap away. Make slits or holes in the bottom for drainage. If you cut large holes in the bottom, you may want to put a coffee filter or some other material in the bottom to prevent the soil from leaking out. Fill the bottom half of jug with potting soil and water it thoroughly. Plant the seeds according to the packet’s directions. At this point you want to label the container in some way. You can write on the outside with a waterproof marker, but I like to re-use the jugs, so I use inexpensive plastic garden stakes, write the name and date on the stake, and stick it in the soil after I’ve planted the seeds. The first time I planted jugs, I used duct tape to tape the jug closed. You can also use a hole punch (or ice pick) and punch a hole in the front of the top half of the jug near the cut edge. Then punch another hole in the bottom half of the jug just below it. When you have planted the seeds and are ready to close it up, thread a twist tie through both holes to keep the jug closed. Then find a spot outside where your pets won’t bother them. Once the sun becomes warmer and the seeds begin germinating, you can uncover them, but be prepared to recover them if the temperatures drop. You also need to check now and then to be sure the soil has not dried out. If the soil looks a little dry, I just give them a few squirts from my spray bottle of water. If they become very dry, set the jugs in another container and water from the bottom so as not to disturb the seeds/seedlings.
If you are a beginner at starting seeds, choose some that germinate easily such as zinnias, marigolds, or tomatoes. But the process works for anything — annuals, perennials, vegetables, and herbs – and it’s fun to experiment. For more details, photos and frequently asked questions, check out www.wintersown.org or the Winter Seed Sowing forum at www.gardenweb.com. Experienced starters say that the mature plants are healthier and hardier than those started inside. For me, it’s a way to chase away the winter doldrums and keep gardening.
Janice Irwin is an OSU Extension Master Gardener volunteer