Can an Ekodome greenhouse stay warm in below-zero temperatures?
Guidance for growers using polycarbonate greenhouse domes in winter and sub-zero climates.
Yes. An Ekodome greenhouse can maintain workable growing conditions in below-freezing temperatures, but the polycarbonate structure alone is not enough to keep the interior warm without assistance. Greenhouses are not insulated buildings; they are solar-heated environments that hold warmth only when heat is either generated or retained effectively.
Our Greenhouse Domes use the Original Ekodome frame paired with full polycarbonate glazing in either solid or twinwall formats. For cold climates, most growers choose 8 mm twinwall polycarbonate, because the internal air pockets provide natural thermal buffering and slow down heat loss.
Twinwall Polycarbonate Benefits
• Better heat retention than single-layer glazing
• Diffused light, reduced hotspots
• Lightweight and impact-resistant
• Effective for cold-weather growing with proper winterization
Twinwall improves thermal performance, but it will not prevent freezing on its own during extended periods of sub-zero temperatures.
How to Maintain a Stable Greenhouse Temperature in Winter
To keep interior temperatures above freezing, especially in harsh winter environments, growers typically use a combination of the following strategies:
1. Supplemental Heating
A reliable heat source is essential during nights or long cold spells.
Options include:
• electric heaters
• propane heaters
• passive solar heating systems
• small wood stoves (with proper venting and sealed penetrations)
2. Thermal Curtains or Insulating Blankets
Used at night to reduce radiant heat loss.
These create a second barrier and significantly slow heat escape.
3. Thermal Mass
Materials that absorb heat during the day and release it overnight, such as:
• water barrels
• stone
• masonry blocks
• dark-colored mass elements placed in sunlight
4. Air Sealing
Tight seals around:
• doors
• vents
• operable windows
• panel edges
Heat loss from small gaps is the biggest cause of temperature drops in winter greenhouses.
What to Expect
A dome greenhouse is absolutely usable in cold climates, but it behaves like any greenhouse structure:
• It captures solar energy efficiently.
• It slows heat loss better than flat-wall structures.
• It still requires supplemental heat when temperatures drop far below freezing.
Many growers successfully use Ekodome Greenhouse Domes for year-round cultivation in northern climates by combining twinwall glazing with the winter strategies above.
Need help selecting the right configuration for your climate?
Email info@ekodome.com with your location and planned dome size, and we’ll point you in the right direction.