If you’re in a cold climate, having a greenhouse is a really effective way to extend your growing season on both ends. In March and April, greenhouses are great for early season greens and to grow out your seedlings. They also allow for additional growing time beyond our first frost date in the fall. With the unpredictable weather that’s guaranteed with a changing climate, having a greenhouse adds a layer of resilience to your garden and homestead.
A complaint that I’ll often get from clients, however, is the cost of heating a greenhouse early in the season. While it gets sufficiently hot during a sunny day, our nighttime temperatures in early spring often dip well below freezing. And while a spring salad is beautiful to have on your plate, you may not feel like it’s worth the heating bill. Even more importantly for me is the burning of fossil fuels that comes with that heating bill (if you aren’t on solar or wind). So if there’s a way to get spring greens without having to heat the greenhouse, I’ll always choose that route.
In my video below, I talk about a strategy I use in my greenhouse that allows me to grow cool season crops without heating the greenhouse, even when the nighttime temperatures are still well below freezing (down to 13°F). With a combination of hoops, frost cloth and blankets, cool season crops like mustard greens, arugula, spinach, bok choy and brassicas can grow without supplemental heat.
Click on the video below to hear more!