How To Insulate A Greenhouse

How To Insulate A Greenhouse 1

The ways on how to insulate a greenhouse is straightforward; you just need some bubble wrap, cold frames and cloches, and pots. Greenhouses are what help your plants get through winter and even just a cold night. But a greenhouse alone cannot trap the heat inside it.

To help with this problem, setting up proper insulation will help protect your plants. Insulation will help keep the insides of the greenhouse warmer and protect your plants from freezing.

So, let’s find out the ways on how to insulate a greenhouse. Just read on!


Before Insulation

A necessary step before you start to insulate your greenhouse is to do some block drafts. Block drafting is sealing gaps, replacing broken panes, and overall making sure that your vents and doors are securely fit.


Ways Of Insulating Greenhouse

Now that you’ve done block drafting, it’s time for you to follow the steps. Here are the simple ways on how to insulate a greenhouse:


#1 Using a bubble wrap/ plastic

With lining your entire greenhouse in bubble wrap or any plastic, this will create double glazing. When you double glaze your greenhouse, it seals away air gaps and reduces the amount of heat escaping the area. Bubble wrap is the cheapest material for insulation like this.

There are various kinds of bubble wraps, and we suggest that you opt to choose the bigger ones. With bigger bubble wraps, more light can pass through, and it provides more insulation compared to small bubble wraps.

These bigger bubble wraps are known as purpose-made horticultural bubble wrap, which is UV stabilized. This type is more durable than the usual bubble wrap you find in your packages. It will last you longer compared to the common ones.

But, if you have a lot of the small bubble wrap lying around in your house, then it would be better that you put it into use. Instead of purchasing the horticultural ones, use what you already have. You’ll save the environment that way.

There are different ways to attach bubble wrap to your greenhouse since there are also different types of greenhouses. If your greenhouse has aluminum frames, then use clips to attach the plastic to the inside of the frames. If the greenhouse has wooden frames, use a staple gun or drawing pins to attach them.

You must insulate the roof as well.

Your greenhouse needs overall protection. For the doorway, let the bubble wrap loosely hang so that you enter and exit the greenhouse.

Insulation is mostly applicable when you feel that your plants will not survive through winter. Insulation reduced the transmission of light. It is essential in cold winter conditions.

Even though it is winter, do remember that snow has insulating properties too. It serves as a great blanket for your greenhouse. You may have to remove some snow on the side of your greenhouse when the sun is facing so that light can enter.


#2 Insulating at night

Heat can build up inside your greenhouse during the day and can be trapped at night using some materials. Purpose-made thermal screens and blinds can work well as night insulators, but they are expensive.

We suggest using two to three layers of row cover fabric as a cheaper alternative. Lay the fabric on top of your plants to trap the heat that has build-up throughout the day.

Heavy materials like old blankets work well too. Blankets are heavy to lay on your plants and might destroy them, so better suspend them on canes or hoops. For the greenhouse itself, a thermal insulation foil covering the insides and the roof will help with the insulation.

The only problem with thick opaque materials is that light cannot easily pass through them. You have to remove the covers during the day to let light get to your plants. These thick insulators are perfect during the night, especially when it is cold.


#3 Utilizing cold frames and cloches

Cold frames and cloches are two materials that are mostly for outdoor use. But, what people don’t know is the useful properties it has for insulation.

We have a great recycling tip for you! Plastic bottles can be used to make tiny cloches. Simply, cut the pet bottle in half and use each to cover your plants. Use a transparent bottle or plastic container so that light can still pass through.

Remember that insulation traps heat, so always remove them when it is too sunny outside. If you keep the covers on for a long time, it might overheat your plants and kill them. Return the cloches when the day is almost over so that heat can build up once again inside them.


#4 Using insulating pots

The most vulnerable plants during the cold are those that are in pots. It is extreme to the point that the roots get frozen. There are a few ways to solve this problem. You can choose to wrap your pots in bubble wrap and help cover the cracks on the surface of the pot.

Another solution is to place your potted plants in soil sacks with dry bracken, straw, or crunched up newspaper stuffed inside.



There are a lot of ways on how to insulate a greenhouse. You can be creative in the process. If ever there are more environmentally-friendly alternatives, do not hesitate to use them. It is better to recycle old materials than to throw them away.

Doing the insulation process correctly can go a long way. This will help your plants survive the cold night or during the winter season.

How useful was this post?

Click on a star to rate it!

Average rating / 5. Vote count:

No votes so far! Be the first to rate this post.

We are sorry that this post was not useful for you!

Let us improve this post!

Tell us how we can improve this post?

Read also

Garage and storage tents

Garage tent for camper van

A garage tent for a camper van is one of the purchase that every caravanning fan should consider. Needless to…

Read more
Polytunnels from A to Z

7 reasons to buy a polytunnel

There are many incentives to buy a foil tunnel. In the following article, we will only mention seven reasons to…

Read more

Polytunnel on rail

A movable polytunnel is a term for a greenhouse which has been designed in such a way that it can…

Read more