How Do I Keep My Greenhouse Warm? Easy Way

For gardeners, the greenhouse is a magical place. You can grow plants that you would normally only be able to find at the local nursery or farmers’ market. 

But with all these benefits comes one major drawback: keeping your greenhouse warm in winter. 

The good news is that this isn’t as hard as it sounds plenty of things can help keep your greenhouse warm during those cold months!

How I kept my greenhouse warm this winter!
– Maintaining proper temperature in a greenhouse is essential for the optimal growth of plants.
– There are various methods to keep a greenhouse warm without using electricity.
– Shading can help regulate the temperature inside a greenhouse and protect plants from excessive heat.
– Insulating the greenhouse can prevent heat loss and maintain a stable temperature.
– Using natural heating methods such as compost or thermal mass materials can be sustainable options.
– Understanding the lighting requirements for plants and providing adequate illumination is crucial for a warm greenhouse.
– Proper ventilation is important to control the temperature and humidity levels in a greenhouse.
– Monitoring the temperature regularly and adjusting heating methods accordingly can help maintain a warm environment.
– Choosing the right heating system based on the greenhouse size and specific needs is important.
– Consideration should be given to energy-efficient practices and alternative heating methods to reduce environmental impact.

1. Grow The Right Plants

You want to grow plants that can tolerate cooler temperatures and weather, especially if you live in a region where winter temperatures are below freezing for long periods of time. 

If your greenhouse is not heated and doesn’t have a supplemental heat source, then it’s important to choose hardy plants that can withstand cold weather. 

Some examples of common plant choices include strawberries, asparagus, artichokes and rhubarb

When it comes to shading a canopy, there are various techniques you can use to provide relief from the sun’s heat. Our detailed guide on how to shade a canopy explains different shading methods that can help you maintain a comfortable environment inside your greenhouse.

2. Insulate Your Greenhouse

To keep your greenhouse warm, you’ll need to insulate it—a lot. You can do this in several ways:

Use polystyrene insulation boards to insulate the roof and walls. Polystyrene sheets are also an option for those who want a lower price tag, but they won’t be as effective at keeping heat out of the greenhouse.

Use polystyrene insulation sheets to insulate the roof and walls of your greenhouse if you want a cheaper option than using polystyrene boards throughout. 

This will help keep cold air from seeping through gaps in your structure, but may not be as effective as fully covering all surfaces with polystyrene boards (which is why we recommend doing both).

3. Use Plastic Or Glass Covers

Placing a plastic or glass cover over your greenhouse will protect plants from cold and wind.

Plastic covers are good for controlling temperature, but they also tend to become very hot in direct sunlight. 

They are great for protecting plants from frost and cold winds, but if there is a lot of light coming into the greenhouse, this can cause heat problems inside the structure.

Glass covers are better when it comes to controlling light levels in the space. They block out more of the sun’s rays than plastic options do and therefore keep temperatures down a little better than their plastic counterparts though they still tend to be too warm if left in place all day long (especially when combined with other methods). 

The downside is that some glass materials can become dangerously hot during sunny days!

Are you considering a tunnel greenhouse for your gardening needs? Before making a decision, it’s important to understand the costs involved. Check out our article on how much a tunnel greenhouse costs to get insights into the expenses associated with setting up this type of greenhouse.

4. Insulation Of Benches And Walkways

You can also use insulation blankets, plastic sheeting and wood pallets to insulate your greenhouse benches. 

This is especially useful if they are raised up off the ground. If you have a large area in which to grow plants, wooden boxes or even hay bales may be an option as well. 

Straw mats and straw rolls offer more protection than hay bales; however, they tend to be more expensive and take longer to install.

Insulation TypeDescription
Reflective Bubble InsulationMulti-layered insulation with reflective surfaces to reflect heat back into the greenhouse.
Polystyrene Foam BoardRigid foam boards with high insulation value and moisture resistance.
Fiberglass InsulationLightweight and versatile insulation material that provides thermal protection.
Polyethylene FoamClosed-cell foam insulation that offers excellent insulation properties and durability.
Thermal BlanketsInsulating blankets designed to cover benches and walkways to retain heat.

5. Install A Fan

To keep your greenhouse warm, install a fan. Fans can be installed to blow warm air into the greenhouse, or they can be used to pull cold air in from outside. 

They can even be used to circulate air inside the greenhouse so that all plants are evenly warmed and cooled throughout the day. 

This is particularly important if you’re growing cold-tolerant plants like tomatoes or cucumbers, as these plants may benefit from being kept at cooler temperatures than other crops. 

You might also use fans for drying out plants after watering – this will help prevent mold growth and prevent bacteria from spreading through your crop!

6. Install A Heater

You can also install a heater to keep your greenhouse warm. Heaters can be expensive to install and are not recommended if you don’t have the proper insulation in place. 

If you do decide to use a heater, make sure it’s placed near an outlet so that it’s easily accessible for maintenance.

Building a greenhouse out of plastic can be an affordable and effective solution. If you’re interested in constructing a greenhouse using plastic materials, our comprehensive guide on building a greenhouse out of plastic provides step-by-step instructions and valuable tips to help you get started.

7. Trust Nature’s Ability To Regulate Temperature

A greenhouse does not have to be heated with electricity or fossil fuels. It is an extension of the earth and will absorb sunlight, then release that heat through the night to keep plants warm at night.

8. Use Cold Frame Heaters To Heat Up Plants During Winter Nights

If you’re growing plants inside your greenhouse, then you can use cold frame heaters to help them grow better during the wintertime.

  • How to use a cold frame heater?
  • How to set up a cold frame heater?
  • What kind of fuel should be used for cold frame heaters?
Heater BrandDescription
FrostGuard ProCompact and efficient heater designed specifically for cold frames.
Greenhouse SolutionsOffers a range of cold frame heaters with adjustable temperature settings.
BioGreenProvides energy-efficient cold frame heaters with built-in thermostats.
GardmanOffers portable cold frame heaters with multiple heat output options.
VegTrugFeatures innovative cold frame heaters that use solar energy for eco-friendly heating.

9. Plants Can Insulate Other Plants From The Cold

As you know, plants can be used as a heat source. In fact, they can insulate other plants from the cold by absorbing excess heat and releasing it at night when it’s needed most.

Plants also serve as a type of “heat sink”, which means that they are able to absorb and store energy over time. 

For example, if you have a plant in your home or greenhouse that is not getting enough sunlight or water, this may cause your plant to become stressed. 

When this happens, the leaves will turn brown and die off which allows more sunlight and water to reach the remaining leaves (or roots). 

The green pigment found in leaves absorbs light energy while red pigments reflect back some of that energy into space which helps keep things cool!

As I mentioned earlier in this article plants are known for their ability to insulate against cold winds too! 

This makes sense because trees often grow taller than humans so they offer great shelter from harsh weather conditions such as rain showers while also providing shade during hot summer days.”

To ensure your greenhouse stays warm and protected, proper waterproofing is essential. Our easy-to-follow guide on how to waterproof a greenhouse outlines the best practices and materials to use, helping you safeguard your plants and maintain an optimal growing environment.

10. Grow Long Season Crops In A Greenhouse

Long-season vegetables take up to 100 days to reach maturity. These include tomatoes, pepper, cucumber and beans. 

In comparison with short-season vegetables that take 50 days or less to produce fruit; such as lettuce, spinach and cabbage.

11. Paint Your Greenhouse With The Right Color Paints

Paints that reflect infrared radiation (heat) and ultraviolet light are the best paints to use on your greenhouse.

The paint should be able to absorb or reflect heat in order for it to protect your plants from cold weather.

WhiteReflects sunlight and helps keep the greenhouse cool.
GreenBlends well with surrounding foliage and provides a natural look.
ClearAllows maximum sunlight penetration for optimal plant growth.
Light GrayProvides a neutral and modern appearance.
BlueOffers a calming and aesthetically pleasing choice.
RedCreates a bold and vibrant statement.
BrownMimics a natural wood-like appearance.

12. Choose The Right Site For Your Greenhouse

You may have to choose a new location for your greenhouse, or you could move the existing one to another area. 

If you are starting with a brand new greenhouse, then you can choose an ideal spot that has good sunlight and access to water (if applicable).

One of the main benefits of choosing a good site for your greenhouse is less maintenance work in the long term. 

If it is difficult to get around in your greenhouse, then it will be more difficult to maintain and keep clean. 

Also consider whether there are any obstacles such as fences, walls or trees which could affect how easy it is for you to tend to your garden through out the year?

Lighting plays a crucial role in the success of your greenhouse. If you want to understand the lighting requirements for different plants and how to provide adequate illumination, check out our informative article on how much light you need in a greenhouse. Discover the optimal lighting levels and techniques to support healthy plant growth.


So there you have it. We’ve covered the basics of greenhouse heating, and hopefully you’re feeling more confident in your ability to keep your greenhouse warm! 

Remember that there are lots of different ways to heat a greenhouse, and any one of them can work well depending on your individual situation. 

If you have any questions or comments about this blog post, feel free to leave them below!

Further Reading

Here are some additional resources to further explore the topic of keeping a greenhouse warm:

Keeping the Greenhouse Warm Without Using Electricity: Discover alternative methods and techniques for maintaining warmth in your greenhouse without relying on electricity. Learn about sustainable and eco-friendly options for heating.

How to Keep a Greenhouse Warm in the Winter: Get expert insights on effective strategies and tools to keep your greenhouse warm during the winter months. Explore practical tips for insulation, heating systems, and winter-specific challenges.

How to Heat a Greenhouse: Learn about different heating methods and equipment options to effectively heat your greenhouse. Discover how to choose the right heating system based on your specific needs and budget.


Here are some frequently asked questions about keeping a greenhouse warm:

How can I insulate my greenhouse?

Insulating your greenhouse can help retain heat and protect your plants. You can insulate it by adding bubble wrap, installing double-glazed panels, or using specialized greenhouse insulation materials.

What are some natural heating methods for a greenhouse?

Natural heating methods for a greenhouse include using compost, installing thermal mass materials like water barrels or bricks, and utilizing solar energy through passive solar techniques.

Should I use electric heaters in my greenhouse?

Electric heaters can be effective for heating a greenhouse but may increase electricity consumption. Consider energy-efficient models or explore alternative heating methods to reduce reliance on electricity.

Can I use mulch to keep my greenhouse warm?

Yes, applying mulch around the base of plants can help regulate soil temperature and minimize heat loss. Organic materials like straw, wood chips, or shredded leaves can act as insulating layers.

How do I prevent heat loss in a greenhouse at night?

To prevent heat loss in a greenhouse at night, you can use thermal screens or curtains, close vents and doors, and add additional insulation layers. Monitoring the temperature and adjusting heating accordingly can also help maintain warmth.