If you would be interested in building your own cold frame, we still have spots in our Cold Frame Workshop coming up on February 17. Please register ASAP online!
Have you seen the winter sowing/season extension display in the outdoor garden area at Fairlington Community Center (FCC)? It was created by two 2017 Master Gardener interns, Jasmin and her mother, Georgia, as a part of their MG intern project. It illustrates how easy and effective growing plants outdoors in winter in Zone 7b can be, anywhere there is a small space and a bit of sun.
Winter sowing as a seed-starting method is fairly easy and inexpensive. The interns started with empty gallon milk jugs, though any transparent or semi-transparent jugs would serve. Georgia placed a few drainage holes in the bottom of each jug and sliced the jug circumference all around, except for about 2 inches which was left as a hinge.
Each jug, without lids, was then filled to a depth of 3 inches with a quality potting mix with added perlite and vermiculite. After soaking the jugs in water, and draining, they planted the jugs with frost-tolerant vegetable and perennial flower seed. The seed was chosen based on the time of year planted.
Winter sowing is all about timing. Any seed can be sown up to 30 days earlier than what a seed packet recommends using this method. Each jug serves as its own small greenhouse, generating heat 10 to 20 degrees higher than the surrounding outdoor temperature. Currently, seeds that were planted in the jugs at Fairlington on Jan. 13 have germinated.
Along with the winter-sown jugs in the FCC garden area, Jasmin and Georgia have placed a homemade cold frame. The design chosen is a bottomless, angled box with a well-fitting glass lid. The cold frame was put directly on the soil surrounding the area where the seeds were planted, facing south. The cold frame, using solar energy, creates a warmer micro-climate, allowing for quicker start for collards, spinach, lettuce, and kale. These plants can continue to grow, extending our already substantial zone 7b growing season and providing MG gardeners with salad greens from FCC’s garden on the coldest of winter days.