Winter Seed Sowing: Making Mini Greenhouses

Winter Sowing

I subscribe to a blog by Kevin Lee Jacobs called “A Garden for the House.”   His most recent entry showed a way to winter sow seeds that is easy, inexpensive, and very successful.  I don’t have garden space for a lot of vegetables, but I do have room for quite a few pots.  Yesterday I sowed kale, Italian parsley, and spinach in 1 gallon water jugs according to Kevin’s directions, and am excited to look for emerging shoots as we move toward s

Perennial seeds and seeds for cold weather crops can be sown anytime over the winter because they will safely wait to germinate in their mini greenhouses until the weather warms up.  Save the seeds for tender annuals and perennials until later, maybe April, when they won’t be nipped by a sudden freeze.

The method is simple.  Poke holes (about 15) in the bottom of a gallon milk or water jug.  I used a Phillip’s head screwdriver that I heated red hot in the flame of one of the burners on my gas range.Drainage holesAdd 3 holes per side about 5 inches from the bottom for ventilation and needed air circulation.  With a sharp knife, cut across the jug 4 inches from the bottom, but not all the way around.  Leave a 2-3 inch section uncut as a “hinge” so you can open your greenhouse when it’s time to transplant the seedlings as the weather warms up.Making a hinge on the greenhouse

Dampen enough light and airy potting soil to fill the jugs about 2-3 inches deep, but below the cut line.  Sprinkle the seeds over the damp soil.  No need to cover the seeds as deeply as the seed packet suggests, and perhaps not at all.

Tape over the cut with duct tape to hold the greenhouse together, although it’s not necessary to make a perfect seal.  Do not replace the cap as the opening permits rain and snow to keep the soil moist.  Place outdoors in a sunny location.  Mine are in a large tub with some pots of transplanted perennial divisions I made last fall.  You can forget about your greenhouses except to check periodically for sprouting or to add moisture if the weather has been dry.  And wait for spring!