The joy of winter gardening in the best year round greenhouse for cold, wind and snow
Winter gardening in your Growing Dome greenhouse is an amazing experience. Walking in your dome from the lifeless vegetation outside into a thriving garden is both enlightening and empowering.
The ability to grow fresh produce year-round is a major benefit of the Growing Dome geodesic greenhouse kit. Furthermore, winter greenhouse gardening is possible without supplemental heat, as long as you are growing cold tolerant plants.
The Growing Dome Greenhouse 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 heating systems, even in the heart of winter.
Through the design of its systems, the Growing Dome Greenhouse comes equipped with its own internal heaters…
Furthermore, given the amount of insulation, heat sinks, and the inherent energy efficiency of its geodesic shape, it requires a third less energy than a traditional greenhouse. It can withstand winter temperatures down to zero outside, while not freezing inside. Letting your greenhouse get ‘cool’ in the winter also helps control bugs.
With over 30 years of experience, we know that the design is sound and effective, which means that we have confidence that you can grow winter frost hardy plants without additional heating of your Growing Dome Greenhouse.
There are still a few reasons why you might want to heat your greenhouse in the winter.
- You are growing tropical plants, tomatoes or plants that like warmer temperatures year round
- You live in a zone that gets <50% sunlight per day in the winter
- Temperatures consistently get into the single digits or below at night in the winter
- You live in a northern climate, USDA planting zone 4 or lower
This article shows what plants thrive in the winter without supplemental heat, but we will also recommend when and what type of heaters you should use in your Growing Dome Greenhouse.
Winter Greenhouse Gardening: Frost Hardy Vegetables
The best time to start your winter growing season is in late August, or early September, but we have had success with fast-growing crops as late as October. Most of the perennial crops, like Oregano, will live happily in the geodesic greenhouse year-round, but it is best to start them in the spring so they have plenty of roots and shoots before winter.
The following cold hardy crops are categorized by their scientific family names. Focusing on edible herbs, leafy greens, a variety of lettuces, and root vegetables, this list is by no means exhaustive. Fruiting crops like tomatoes or cucumbers are best started in late winter or early spring and grown all summer long. Tomatoes can make it through the winter and live for years if properly maintained and fed, but it takes extra effort, time, and energy, depending on your climate.
These winter vegetables and medicinal crops have been grown successfully through the cold season in our Growing Dome greenhouse kits without supplemental heat. For a full planting schedule for all times of the year, click here.
Amaryllidaceae Family (aka. Amaryllis Family)
Green or Bunching Onions
Apiaceae or Umbelliferae Family (aka. Carrot, Celery, or Parsley Family)
Cilantro (aka. Coriander)
Asteraceae Family (aka. Daisy Family)
Brassicaceae Family (aka. Cabbage, Cruciferous, or Mustard Family)
Fabaceae Family (aka. Bean, Legume, or Pea Family)
Sweet Pea or Sugar Snap Pea
Lamiaceae or Labiatae Family (aka. Mint, Sage, or Deadnettle Family)
Catnip or Catmint
Tropaeolaceae Family (aka. Nasturtium Family)
Heating Your Growing Dome Greenhouse 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.
Growing Dome Heat Loss Calculation Spread Sheet
Calculate exactly how much heat is required to reach a desired temperature inside your Growing Dome
I have a number of friends here in Pagosa Springs, Colorado, who have chosen not to heat their Growing Dome greenhouses. This is also the best way to control pests, as they prefer a warmer climate.
I personally have only heated my personal 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 Dome greenhouses, we use a Mr. Heater in the winter.
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.
We recently purchased a new Mr. Heater 30,000 BTU Propane Vent-Free Blue Flame Wall Heater for our 26′ Growing Dome, that has a thermostat control.
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 greenhouse 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 greenhouse gardening video below to see the different types of heaters and what happens to the plant growth if they freeze.
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