How Do You Keep Greenhouses Warm? (Easy Ways)

Greenhouses can be a great way to add an extra layer of warmth in your home, especially during the winter months. 

They can help keep your plants alive and thriving during cooler seasons, and they are also a fun project for DIYers who want to try their hand at building one themselves. 

But how can you keep a greenhouse warm? This guide will show you everything from solar heaters to geothermal units so that you know exactly what type of heating system is right for your greenhouse and how much it will cost (or save!).

How I kept my greenhouse warm this winter! – YouTube
Proper insulation is crucial for keeping greenhouses warm.
Using thermal curtains or bubble wrap can help retain heat and prevent heat loss.
Implementing proper ventilation systems can regulate temperature and prevent overheating.
Utilizing alternative heating sources, such as compost heaters or solar energy, can be cost-effective and environmentally friendly.
Monitoring and controlling temperature through thermometers, thermostats, and automated systems is essential.
Creating shade with shade cloths can help regulate light and temperature levels inside the greenhouse.
Mulching the soil can provide insulation and prevent freezing temperatures.
Consider using heat sinks or thermal mass to store and release heat throughout the day and night.
Implementing proper water management practices can help maintain a warm and humid environment.
Regular maintenance and inspection of the greenhouse structure ensure its efficiency in retaining heat.

1. Light the Plant-Heating Chimney

The most basic way to heat a greenhouse is through passive solar energy, which means using the sun’s rays to warm your plants and clear out any lingering fog. 

This method requires you to build an insulated chimney (also called a solar funnel) on one side of your greenhouse. 

Then, place a light bulb inside that will absorb heat from the sun and transfer it through the chimney into your greenhouse. 

The best type of bulb for this purpose is incandescent because its filament doesn’t get hot enough to prevent plant growth but still produces enough heat for them growing within its reach range

Finding the right balance of light is crucial for the success of your greenhouse. Learn about the importance of light in a greenhouse and discover how to optimize lighting conditions for your plants. Read our comprehensive guide on how much light you need in a greenhouse to ensure healthy growth and maximize your yield.

2. Install a Wood Stove

A wood stove is another way of keeping your greenhouse warm. A wood stove can be installed in the corner or along an outside wall of your greenhouse. 

You’ll want to make sure that your wood stove is installed properly, as it can become a fire hazard if not installed correctly. Some things you need to consider when installing a wood stove include:

How many people will be using the space? The number of people who will be using the space determines how large the firebox should be and how much wood you need to burn each day.

Is there an exhaust system? If so, what kind? If not, is there enough ventilation through open doors and windows? Open doors and windows provide adequate airflow for most stoves; 

However, if you have any concerns about air circulation or safety hazards due to drafts caused by opening doors or windows too wide (which could potentially cause smoke inhalation), consult with experts before installing any type of heating device inside your home at all!

3. Block Wind from the Doors and Windows

Windbreaks are a great way to keep out the chill of winter, and they’re especially useful in greenhouses. They help with insulation, too.

There are a variety of windbreaks that you can use: straw bales, hay bales, logs/lumber/lumber planks (with or without nails), rocks (also called “sills”), sandbags (and sandbags filled with soil).

4. Paint the Greenhouse with a Dark Color

The color of your greenhouse has an impact on its temperature. Dark colors absorb heat, which means that you will find it easier to maintain a consistent temperature in a black greenhouse than in a white one.

Black is the best color for capturing heat, followed by dark green and light green. These three colors will help keep your greenhouse warm while also providing some protection from harmful UV rays. 

White is ideal if you’re looking to reduce heat loss as much as possible but have no need for sun protection; however, white can create glare if it’s not properly covered with reflective material or tinted glass.

Protecting your greenhouse from water damage is essential for maintaining a warm and functional environment. Our step-by-step guide on how to waterproof a greenhouse provides practical tips and techniques to keep your plants safe and dry, ensuring optimal growing conditions even during rainy seasons.

5. Install Sun-Tracking Solar Panels

If you’ve got a greenhouse, it’s probably pretty obvious that there are lots of windows. These windows let in sunlight, which is what makes greenhouses so great. 

The problem is that they also let out heat and if you’re growing vegetables or flowers inside your greenhouse and have it open during the wintertime, you’re going to need something to keep the cold air out.

There are two options: 1) close your greenhouse every day at sunset, or 2) invest in some solar panels for your roof. If you choose option 1, good luck! But if you want to go with option 2? That’s easy!

Solar panels can be installed on the roof of your greenhouse and generate electricity during the day via solar energy from the sun hitting them directly (or indirectly through mirrors). 

This electricity goes into an attached battery which stores enough power to power lights and fans at night when temperatures drop below freezing point outside

SolarTechSun-tracking technology
PowerMaxEfficient solar panels
EcoSunEnvironmentally friendly materials
SolarSenseRemote monitoring and control
SunGuardWeather-resistant design

6. Use Reflectors for Even Heat Distribution

Reflectors are made of materials that reflect the sun’s rays. You can use a variety of materials in your greenhouse to reflect heat, depending on the time of day and where you live. 

For example, if you live in an area with lots of snow, then it may be better for you to use a reflective material that won’t melt or warp due to high temperatures (such as aluminum foil). 

If your greenhouse is located near heat-absorbing surfaces such as trees or rocks, then using layers of glass might be best so that it doesn’t absorb too much warmth from those surfaces.

Here’s how one expert recommended using different types of reflectors: “Depending on its location and purpose in your garden, choose a material that is appropriate–for example frosted glass will not work well behind crops like lettuce since this will inhibit light penetration.”

7. Use Thermal Curtains or Insulated Curtains

If you’re looking to keep your greenhouse warm, there are two options for covering your windows and doors: thermal curtains and insulated curtains. 

If you’re on a budget, go with the former option a roll of black-out fabric can be purchased at most hardware stores for around $20 (plus some scissors). Just cut the fabric to size and attach it around the frame by stapling it in place.

If you want something a little more professional-looking than what you could make yourself, insulated curtains are available from companies like Grower’s Supply Company; these come with top-quality fabrics that will help trap heat inside your greenhouse for an even greater effect than regular black-out drapes would have.

Either way, these kinds of insulating materials are effective at keeping heat from escaping through windows and doors into the cold outside air during winter months when temperatures drop below freezing; this is important because without proper insulation those areas may freeze up!

Looking for efficient heating solutions for your cattle panel greenhouse? Discover innovative methods and expert advice on how to heat a cattle panel greenhouse without breaking the bank. Explore different options and find the perfect heating strategy to keep your plants cozy and thriving.

8. Dig a Greenhouse Pit

A greenhouse pit is a great way to keep your greenhouse warm in winter. A pit is basically any kind of underground structure that raises the soil temperature by storing heat from the sun, which can then radiate up through the ground and into your greenhouse.

It’s important to note that digging a pit isn’t something you’ll want to do with any old shovel you’ll need a pneumatic posthole digger, which can be rented at most hardware stores for anywhere between $30-$60 per day or $100-$160 per week (depending on where you live).

The first step in digging your own pit is finding an appropriate location for it. You should choose somewhere close enough that heat from it will easily reach your greenhouses but far enough away so as not to add excessive moisture onto plants or become too hot inside those greenhouses themselves (which could cause them to melt).

Next comes scooping out soil and breaking up rocks using whatever tools you have available (a pickaxe works well) until you hit compacted gravel beneath; this ensures there won’t be any air pockets when finished with this process!

BrandPit Depth (ft)Pit Width (ft)Pit Length (ft)

9. Cover the Roof and Walls of the Greenhouse with Polythene Film

Polyethylene film is a good insulator. If you cover the roof, walls and floor of your greenhouse with polyethylene film, it will keep the inside of the greenhouse warm and prevent cold air from entering easily. 

This can be done by using rigid sheets or rolls of polyethylene film which are available at hardware stores or agricultural supply stores.

You can also use flexible plastic sheeting that has been treated to reflect sunlight and heat back into the greenhouse instead of letting it escape through windows and vents. 

This type of sheeting is called aluminized bubble wrap insulation because it consists of multiple layers of bubble wrap sandwiched between two layers of aluminum foil for maximum reflection ability. 

To install this type of material over doors or windows in your greenhouses, cut pieces that are slightly larger than each opening so that they overlap at least one inch all around each side when installed on top or bottom edges (depending on whether you’re installing them vertically or horizontally).

Controlling the amount of sunlight that enters your greenhouse is essential to prevent overheating and maintain ideal growing conditions. Learn how to create a shade cloth for your greenhouse and effectively regulate light levels. Our guide on making a shade cloth for a greenhouse provides step-by-step instructions and valuable insights to help you achieve optimal shading for your plants.

10. Insulate it with Bubble Wrap

If you have a greenhouse and want to keep it warm in winter, there are several ways to do this. One of the most effective methods is by using bubble wrap as insulation. 

Bubble wrap has proven itself over time as an excellent insulator, so if your greenhouse comes with little or no insulation at all, investing in some bubble wrap will help keep your plants warm during the chilly months.

The first step will be measuring the walls of your greenhouse to determine how much bubble wrap you need for each wall. 

Once this is done, all that remains is installing it! Simply peel back one layer of protective plastic from each side of the bubble wrap sheet and begin attaching it around corners and edges with duct tape or aluminum foil tape (if available). 

This can be done on both inside and outside walls doing so will provide superior insulation for both summer heat loss as well as winter cold protection

BrandBubble Wrap Thickness (mm)R-Value (m²·K/W)

11. Use Straw Bales to Insulate the Greenhouse Foundation

If you’re in a cold climate, use straw bales to insulate your greenhouse foundation. Straw bales are an excellent way to insulate the walls, floor, and ceiling of a greenhouse as well. 

They’re cheap and easy to work with once you get them into place: just stack them up like bricks!

Planning to build a greenhouse in a snowy region? It’s important to consider the specific challenges and requirements to ensure your greenhouse can withstand the winter elements. Explore our detailed guide on building a greenhouse that can withstand snow and discover essential tips, construction techniques, and recommended materials to create a durable and functional structure that keeps your plants warm and protected all year round.

12. Add a Water Reservoir to the Growing Space

Tired of the cold? Want to keep your greenhouse warm? Good news! You can use a water reservoir to do just that. There are two ways you can go about this:

A large plastic container such as a 5-gallon bucket, or even a bathtub (if you have one). Fill it with water and then drain it out regularly to heat up the air inside the greenhouse.

If you have multiple greenhouses and want them all warm but don’t have enough hot water for all of them, try adding a second reservoir (or more) for each greenhouse instead.


As you can see, there are many ways to keep a greenhouse warm. The most important thing is that you try and find a solution for your own situation. 

If you want to learn more about greenhouses and how they work, check out some of the other articles on our website!

Further Reading

Here are some additional resources that you may find helpful for further information on keeping greenhouses warm:

Heat Your Greenhouse: A Comprehensive Guide: Learn various methods and strategies for effectively heating your greenhouse, including passive and active heating techniques, insulation tips, and alternative energy sources.

Keeping the Greenhouse Warm Without Using Electricity: Discover eco-friendly ways to keep your greenhouse warm without relying on electricity. This article offers creative solutions and sustainable heating options.

How to Keep a Greenhouse Warm in the Winter: Explore practical tips and expert advice on maintaining a warm greenhouse during the winter season. Learn about insulation, heating systems, and efficient energy management.


Here are some frequently asked questions about keeping greenhouses warm:

How can I insulate my greenhouse?

Insulating your greenhouse can help retain heat and maintain a warm environment. Consider using materials such as bubble wrap, thermal curtains, or double-glazed panels to provide insulation and reduce heat loss.

What are some low-cost heating options for a greenhouse?

If you’re looking for affordable heating solutions, you can explore options like using solar energy, compost heaters, or DIY heat sinks. These methods can help regulate the temperature in your greenhouse without relying heavily on electricity.

How do I prevent freezing in my greenhouse during winter?

To prevent freezing temperatures in your greenhouse, you can employ techniques such as installing a heater, using heat-retaining materials, circulating warm air with fans, and utilizing thermal mass to store heat during the day and release it at night.

Can I use mulch to keep my greenhouse warm?

Yes, mulching can help insulate the soil and regulate temperature in a greenhouse. By adding a layer of organic mulch, such as straw or wood chips, you can prevent heat loss from the ground and maintain a warmer environment for your plants.

How can I monitor and control the temperature in my greenhouse?

To monitor and control the temperature, you can use a combination of devices like thermometers, thermostats, and automatic vent openers. Additionally, you can implement shade cloths, ventilation systems, and misting/fogging systems to manage temperature fluctuations effectively.