Best Way To Heat A Greenhouse

The most important benefit of a greenhouse garden is the ability to get any plant or vegetable you desire in any season, at your convenience. Since the conditions inside a greenhouse can be adjusted based on the requirement of the plant to be grown; temperature can be raised in winter and brought down in summer, they are ideal for growing seasonal plants and veggies all-year-round.

In winters when the mercury drops, due to the harsh and cold conditions, the plants can frost and wither, which can make the entire growing activity redundant. These climatic conditions cannot be controlled, but a gardener can definitely work on ways to keep the plants alive. 

One way of doing this is by heating the greenhouse so that the ideal temperature is maintained inside it. However, it is important to follow the correct methods of heating the greenhouse. In this post, we will find out the best way to heat a greenhouse.

Why Heat A Greenhouse? 

best way to heat greenhouse

Heating a greenhouse, especially in winters is of utmost importance. There are times when the sun would be enough to keep the greenhouse warm, but when the weather plummets, artificial heat would be needed to keep the plants in a good shape. 

Along with basic requirements for growth like water, sunlight and CO2, plants also need a suitable temperature for their growth. For example, in winters if you’re growing plants that require a higher temperature, you need to apply some heating methods that will maintain the warmth inside the greenhouse.

You need to keep the plants warm so that they do not frost and get sufficient energy inside the greenhouse to strive. There can be quite a few methods of heating a greenhouse. They have been listed below. You can choose any of these methods to heat your greenhouse depending upon your convenience. 

Types Of Heating Methods

1. Choose Compost

If you have been a gardener for a while, you already know what a compost pile can do. It is smoking hot and it can increase the warmth inside the greenhouse in a very energy-efficient way. 

The compost can get above 150 degrees Fahrenheit in the center of the pile and that can naturally spread heat and keep the greenhouse warm. You can create paths made from wood mulch. When you mulch the beds, it can add to the heating.

2. Use Double-Pane Windows

When the weather outside gets cold, the double-pane windows help conserve the heat from the sun. They are energy efficient and help prevent any sort of heat loss. 

It’s understandable that opting for a double pane window can be an expensive affair for you but in that case, you can also go for clear plastic, which is a cheaper option to create the same effect. This helps seal the heat and once you caulk it, you would have it sorted. 

3. Using Sun As A Heat Source

Direct solar heat is a free source of heat. It’s also one of the heating methods for the greenhouse. The electromagnetic radiation that comes from the sun, is said to heat the inside of the greenhouse, which includes the thermal mass as well. 

 4. Using Electric Heaters 

When you have a small greenhouse, heating it may not be an expensive affair. The best way to keep the interiors heated is by using an electric heater, that has a thermostat. This method works really well if you want a more hands-off approach towards heating.

All you need to do with this heating system is just place the heater inside the greenhouse, set up the thermostat and let it do the job of keeping the greenhouse warm. Nowadays, these heaters come with automatic turn off. 

Hence you won’t have to worry about getting the room extra heated. 

5. Opting For Thermal Mass Objects 

There are so many objects that are helpful to utilise heat in the greenhouses. During the day, they absorb heat from the sun and store it. And in the night time, when the temperature drops, they emit the heat. Such objects are known as thermal mass. You can opt for objects such as clay, bricks, rocks etc. as they absorb heat and are helpful during colder conditions. 

Water works well in such cases as thermal mass. You can make raised beds, with the help of bricks or stones. These objects are said to be good at absorbing heat. You can also use black barrels of water to keep the surroundings warm. 

6. Insulating The Northern Side

It will be worthwhile for you to insulate the  northern side with something like thermal insulation foil. This helps prevent any sort of heat loss and defeats the north winds, from entering inside the greenhouse.

Along with that, with the help of a thermal mass heating system, it is easier to absorb the sun rays. All you need to do is ensure that the northern side of the greenhouse isn’t glass.

7. Insulate With Bubble Wrap

best method to heat greenhouse

When insulating with bubble wrap, use horticultural ones than the ones that are used in packaging. They’re stronger and are able to withstand the harsh UV rays as well. 

Big bubbles grant better insulation and bring in the most light for the plants. To use it, you can staple or tape the bubble wrap. To minimise any sort of light loss, keep the windows clean. 

You can also use bubble wrap insulation for the outdoor plants. They work well in cold weather, protect them from freezing and control cracking as well. 

9. Opt For Power-Free Heated Beds

While other methods including using compost for the greenhouse or heating barrels of water can prove useful, another method is using solar water heating pipes. Use these on closed-loop so it pumps hot water through the garden beds. 

These pipes can be worked around the compost heap. The warmth will heat the water that moves through the pipe and gradually heat the soil as well in the beds.

This doesn’t entirely undermine the importance of a powered heated greenhouse but can definitely keep the plants warm enough for the changing climates.

These were some widely used heating methods. However, to find out the best way to heat your greenhouse, keep reading.

Best Way To Heat Greenhouse 

Keeping the greenhouse warm, especially in colder temperatures is very important. One of the best ways to heat a small hobby greenhouse is by using heaters, whether they are electric, gas or paraffin heaters.

On the other hand, if you have a bigger greenhouse, and live in a place where the winters are extreme, the best way to heat the greenhouse is by first insulating the floor and then making use of compost and water pipes that will eventually heat the soil. In a large greenhouse, you will need heaters with a large output or even multiple heaters which can be a costly affair.

How To Heat A Small Greenhouse With Heaters

When it comes to heating a small greenhouse, simply installing a heater of the right capacity at the right place, can work really well. 

Electric Heater:

best way to heat small greenhouse

Irrespective of the place or how the greenhouse is positioned, you don’t need to set up any other system when you have electric heaters. Electric heaters can be an expensive choice but there are several other options available too. 

As we check out some more greenhouse heating options, especially for a smaller space, these burn some kind of fuel. The following heaters are the best options for that.

Gas Heater: 

which is the best way to heat a greenhouse

Greenhouse gas heaters for example propane or natural gas, are used and they don’t need any electricity. This means that even when there is a power cut, your plants will not be deprived of the warmth inside the small greenhouse. 

Experts advise that people in colder climates should opt for one heater if the greenhouse is between 150-175 square feet. People in warmer locations can own one for 200 square feet.

You can also own tanks of propane and hook them up to a propane heater, in the greenhouse. Safe venting of propane is needed to expel gases and an adequate supply of oxygen for the gas to burn efficiently. 

Paraffin Heater

best method to heat small greenhouse

Paraffin heaters too are a great idea to heat up a greenhouse. They work by lighting a wick and it draws liquid from the holding vessels. These heaters produce air pollutants but they need to be operated in spaces where there is outside airflow available. 

There are several advantages associated with paraffin greenhouse heaters. Firstly, they are cheap and are available in various sizes. 

The running costs of these heaters are kept low. This equipment doesn’t require constant attention. Considering the output of CO2 also improves the condition of the plants. 

Paraffin heaters are also self-contained as they don’t need any electric supply. 

Best Energy-Efficient Heating Method For Larger Greenhouses 

Heating a larger-sized greenhouse with the help of compost is a much cheaper and efficient option.

best way to heat large greenhouse

There are ways in which compost bins can help warm the areas or you can use trench composting. This allows the gardener to keep the heat throughout the cold weather. 

When gardeners make use of this method, it can help the plants thrive all year long, at an inexpensive cost. How, you ask? Let me explain below.

You can utilise two empty barrels to get heat from the compost in the greenhouse. It will give plants the required warm temperatures.  Use 55-gallon barrels and keep them a few feet apart inside the greenhouse. Once done, make sure each of them is covered. Give enough space to the compost with the help of a metal wire bench to put on the barrels for support. 

Then place a wooden box between the barrels and fill it with compost.  Fully load it and raise the temperature when it starts to decompose.  Add water to the new compost bin and make sure to compress it down by standing on it with the help of rubber boots or press it down with gloves. Compost helps generate heat for the greenhouse. You can then place the plants on top of the wire bench, as they will start getting the heat.

You can also keep a thermometer to monitor the heat. 

You can also use solar water heating pipes. These help around the compost heap as well. As said above, it helps the water heat up through the pipe and gradually heats the soil as well, granting warmth to the plants. 

Outdoor plants near the wall of the greenhouse can be covered with the bubble wrap method as mentioned earlier. They help insulate tender plants and keep them warm when the temperature dips. 

Find all this confusing? Here’s a video to help you better understand composting for heating the greenhouse.


Heating a greenhouse, irrespective of the weather condition is actually not a huge task. Once you learn these tricks to keep the heat stacked in the greenhouse, your gardening life will be easier than ever.

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