Winter gardening is a tricky business, but at our market garden, Verdigris, we are experimenting with ways of growing, or at least harvesting vegetables all year round. I tested our soil this morning to see where we were with the single layer of protection, the soil temperature was a consistent 50 degrees F. This will allow things to grow and mature, but direct sown seeds may struggle to germinate and mature properly.
The author Elliot Coleman states that winter crops will thrive inside an old-fashioned cold frame – a bottomless box with a glass or plastic top that you can build (old windows work well) or purchase readymade. “Basically, you’ve changed the climate,” Mr. Coleman explains. “You’ve moved your garden 500 miles [800 kilometres] or one and a half growing zones, south by using greenhouses or polytunnels. Our garden is in zone 6a; with our polytunnel greenhouse, we’ve essentially moved our garden to zone 7a or 7b which extends the season, but to go to zone 8, which allows year round gardening (click here to go to the USDA hardiness zone map), we would need an extra layer of protection. Mr. Coleman says. “That second layer moves you an additional 500 miles south.
We will be building some additional low tunnels for one side of our greenhouse, but I thought we could try to use something we already had. We purchased the Groundworks garden tunnel at the end of the season clearance sale at Tractor Supply. We thought we could use it outside to extend the growing season on one of our beds, but the dimensions don’t make it convenient, so I decided to set it up in our polytunnel.
It sets up quite easily, but one has to be careful to ensure that the aluminum poles are firmly and completely inserted into the connectors or the top plastic cover won’t fit properly.
Once the frame was assembled, I unfolded and applied the plastic cover, which has vents on either end and access/ventilation windows along one side to plant, harvest and vent the greenhouse if needed. I can’t wait to see how it works!