Even though it’s been below freezing at night, I’ve continued to grow vegetables in my portable solar greenhouse. A portable, solar greenhouse is a temporary greenhouse that can be used to accelerate the growth of bedding plants and veggie starts in the early spring. It relies on radiant heat to keep plants warm and gives those of us who live in a cold north climate a two month jump on the growing season.
This is the first time I’ve grown vegetables in cold fall weather and it’s been an interesting experiment. Here’s a few of the strategies I’ve been using to make cold weather fall vegetable gardening possible in a portable greenhouse.
Plugged gaps. Because our solar greenhouse was designed to be used in the spring, it is not very tightly sealed which makes it tough to keep out cold air. One of my winterizing strategies was to apply seals around the door and vents, plug gaps, and pack insulation around the ceiling and the north side of the building.
Insulated where possible. I also added some insulation to prevent heat loss through the ceiling and the doors.
Installed a heat lamp. To keep my veggies warm at night, I dragged an extension cord to the greenhouse for hooking up to a heat lamp. I’m using a 125V reflective plant lamp which keeps my 8′ x 8′ greenhouse about 50 degrees at night.
Monitored day time temps. It’s been cold and overcast these past three weeks, and yet the UVs from the sun are doing a grand job of keeping the interior of the greenhouse a balmy 70-80 degrees. This is the perfect temperature for my vegetable which are continuing to produce blossoms and fruit. For the days that it rains or there is a dense cloud cover, I keep the heat lamp on since these plants need warm temperatures for the veggies to ripen.
Fertilize and water regularly. Because my vegetables and herbs are in pots, they must be watered, fertilized, and pruned quite regularly. At the moment, I’m giving all my plants a deep watering every other day which not only keeps them well hydrated but also adds humidity to the green house. The smaller, potted herbs are kept in trays which are filled with 2″ of water.
Harvest often. The fun part of cold weather vegetable gardening is harvesting foods like fresh peppers and tomatoes, even when it freezing at night. I harvest my produce often which concentrates the plants’ energy into ripening what’s left on the plant. Even though cold weather produce is about 1/3 smaller than the produce I was harvesting this summer, it’s every bit as delicious.
So far, my portable solar greenhouse has been working well at protecting my plants from “mildly” freezing temperatures, which is what it was designed for. It’ll be interesting to discover what will happen once the temperatures drop to the ‘teens which is a typical winter temperature where I live.
More by this contributor:
How to winter compost.
5 gardening mistakes I made this year.
9 ways to get free plants and trees
