Do you need to heat your Growing Dome® Greenhouse in the Winter?
Before I share a few reasons why you might want to heat your Growing Dome in the winter, and what type of heaters we recommend, the short answer to the above question is:
No. You do not need to heat your Growing Dome in the winter.
The Growing Dome is designed as a self-sufficient, net zero energy structure.
It is capable of growing food year round in most climates of the United States, without additional heat, even in the heart of winter.
Through the design of its systems, the Growing Dome comes equipped with its own internal heaters…
Furthermore, given the amount of insulation, and the inherent energy efficiency of its geodesic shape, it requires a third less energy than a traditional greenhouse. It can withstand temperatures down to zero outside, while not freezing inside.
With over 25 years of experience, we know that the design is sound and effective, which means that we have confidence that you can grow food in the winter without additonal heating of your Growing Dome.
In a moment, you’ll discover why we sometimes heat our Growing Domes, and why you might want to do the same. But first, if you choose to have no additional heater…
…you need to grow frost hardy plants. There are many varieties of frost hardy plants that will withstand a little freezing.
Winter Gardening Frost Hardy Crops
Beets, turnips, radishes, rutabaga, daikon, and carrots.
Leafy Crops And All Members Of The Cabbage Family:
Cabbage, kale, collards, brussels sprouts, radicchio, rutabaga, spinach, swiss chard,
onions, garlic, and leeks.
Japanese greens, mizuna, tatsoi, endive, bok choy, and arugula,
All of the herbs grow really well, with the exception of cilantro and basil. But rosemary, sage, oregano, marjoram, thyme, and parsley all do exceptionally well, both winter and summer, in the Growing Dome.
Heating Your Growing Dome In Winter Falls Into Three Main Levels Of Heating
First Level: No heating.
Second Level: Heating if the temperature gets into the single digits.
Third Level: Never letting the Growing Dome freeze.
I have a number of friends here in Pagosa Springs, Colorado, who have chosen not to heat their Growing Domes.
I personally have only heated my 22′ Growing Dome for one week in 15 years. That was after a week of no sun, followed by temperatures in the -20s!
A little ice forming on the tank inspired me to heat it.
However, I have grown many of the above-mentioned crops successfully.
Here is a shot of our 15′ Growing Dome, we are not heating it, and you can see that these frost hardy plants are doing great.
Heating When Temperatures Drop Into Single Digits
At Growing Spaces® we tend to heat our Growing Domes when the temperature dips into the single digits…
…because we want to encourage growth throughout the winter, maintain winter produce for our staff, and present an inspiring environment for our customers to see.
To this end, for our smaller Growing Domes, we use a Mr. Heater.
It has three settings from 9000 BTU to 14,000 BTU which keeps smaller domes from freezing on those cold nights.
The disadvantage is that you have to light the heater at night and turn it off the next morning.
Never Letting The Growing Dome Freeze
A lot of people have frost sensitive plants including citrus and subtropical varieties of shrubs.
In this case, the heater we recommend is called a Southern Burner.
The beauty of this heater is that it is controlled by a thermostat so you can set the minimum temperature that you want the dome to go down to.
The Southern Burner heater gives out 25,000 BTUs which is enough to heat a 33′ Growing Dome very adequately.
If you use a heater of this kind, there will be more condensation on the polycarbonate, which then drips down inside.
Some people have thought their dome was leaking, but this is usually not the case.
Watch the winter gardening video below to see the different types of heaters and what happens to the plants if they freeze.