How to Make a Cold Frame: You’d Be Surprised By How Easy It Is!

How to make a cold frame header

Growing plants during winter is always a hassle. You have to be more meticulous with the plants. To make your work easier, you can use a cold frame to protect seedlings from the cold while still allowing them to enjoy the warmth of the sun.

How to make a cold frame? It’s not hard at all!

What Is a Cold Frame?

As the name suggests, it is a frame, meaning, it has four sides. 

It is referred to as a cold frame being this item is meant to protect plants from the cold weather. 


The frame encases a transparent material. 

This way, while the cold frame protects the plants from harsh, low-temperature weather, they can still enjoy the warmth of the sun. 

In essence

The plants will get natural sunlight while also getting warm from the protection of the cold frame. 


There are cold frames available in the market. You can choose from so many designs and materials. 

But you must also like to know that a cold frame is actually quite easy to make. 

Why take on the hassle?

The cold frame can be cheaper if you make it yourself. 

You can choose the material you want for the supportive structure and the transparent component.

More importantly, you can choose the size that you want. 

In other words

The cold frame will be personalized and will have your personal touch as well. 

Why a cold frame and not greenhouse?

A greenhouse is a whole structure. It’s large and needs a large space. 

It’s also expensive. 


When you create the cold frame, you just need to form sides and cover it with a lid in the form of a transparent top. 

You can be very creative with your sides, actually.

In fact

I saw one that had straw bales surrounding the plants and the lid was placed on top of the organic structure. 

Very creative, right?


Now, it’s really up to you what materials you want to use. The most important thing is that you understand the purpose. 

You want a material that could really protect the plants from the cold. 

Cold frame in garden

Purposes of a Cold Frame

As already mentioned, the cold frame protects plants while also allowing the heat of the sun to touch the plants. 

But let’s be more specific. Here are the important reasons why you should have a cold frame:

  1. Provides dormancy for tropical plants

Don’t expect your plants to keep on growing under the cold frame–it’s not a greenhouse. However, it could allow your plants to have a gentle dormancy. 

What does this mean?

The cold frame gives plants the right surroundings to go dormant. It provides consistency and the right insulation. 

This process is called overwintering. 

Be cautious:

When doing this, make sure that you don’t overwater the plants. Over the winter, plants don’t need so much water. 

Just provide enough to keep the soil moist. 

Also, best that you don’t allow sunlight in so that the plants will not be encouraged to grow. 

How is that bad?

Dormant plants need consistency. That’s why you have to be meticulous and ensure that the plants will have a steady temperature all throughout winter. 

Just let the plants sleep comfortably. 

Don’t worry

The plants will continue growing once winter is over. 

  1. Gives early start for seedlings

Your plants will germinate early. Why? Because it is in a controlled environment. 

You are better off taking care of the plants this way. 

There is also this

There is no need to transplant them as they are already planted directly to the soil. 

It has the controlled living space of a pot. However, you don’t need to transplant the plants when time comes because they are already in the space that they need to be for maximum growth. 

You are basically removing transplanting shock in the equation. 


In some cases, seedlings are still in small pots or trays when they are placed inside the cold frame.

  1. Acclimates seedlings

When you have seedlings in cold frames, you are basically acclimatizing them to the harsh conditions outside. 

When you want them to be hardened by the heat, you open the cold frame. You can do the same during cold weather. 

What does this do?

When plants, especially seedlings, are exposed to the direct heat of the sun, cooler weather and even harsh winds, they become better. 


Their foliage will be thicker and darker in color. Those are indicators of healthy plants. 

Seedlings sprouting
  1. Extends growing season

You know how there are annual and perennial plants? The former have a single growing season while the latter can grow in three or more seasons. 

Now a cold frame allows annuals to become perennials. 

This way

You don’t have to fear the cold season. 

Now on to the more important part…

How to Make a Cold Frame

As earlier mentioned, you can choose the materials you want for your cold frame. As long as the basic merit is there–it can protect the plants from the cold and extreme heat. 

In fact, you can use an old window as your cold frame. Then you just create the sides based on the size of the window. 

However, the most common frame material is wood. 

Here are the basic materials needed for the process:


The basic principle here is that the lid or the top of the cold frame is transparent. It can be glass or a greenhouse plastic. 

You can’t just use ordinary transparent plastic. It has to be sturdy like the greenhouse plastic. 


Now the lid has to be framed, usually with a wood. 


The frame is attached to a box that will shelter the plants. 

The box has four sides and the size should be as big as the lid. Precision is important because you want complete protection. 

Another important thing about the walls–the back should be taller than the front. This means that the sides should be diagonal. 

What tools do you need?

You need to attach the sides of the box together and the cool frame onto the box. So you will need a drill, some screws, and a screwdriver. 

You will also need a few hinges–or more of you plan to make a bigger cold frame. 

Small cold frame in garden

Now, let’s begin:

1. Prepare the materials for the box / walls

I can’t give you dimensions because the size of the cold frame will really depend upon your need. The size would be up to you.

But the basic thing is that there will be four walls and that the back should be taller than the front. The top of the side boards will be sloping. 

You will also need some corner posts where you could screw the sides together. The corner posts would be around an inch in width. The height of the two posts will match the size of the front frame and the two others will match the taller frame at the back. 

2. Screw the four boards to form a wall

You first screw the side boards onto the posts. Of course, drill the holes first.

Then you follow with the front and back boards. Again, you screw them onto the posts. 

3. Attach the lid

Position the lid carefully onto the frame so that it will perfectly cover the frame. 

Screw the hinges. 

In addition:

You need support batons. 

What are support batons? These are the support system for the cold frame so that you can open it for ventilation. 

The baton could be an ordinary stick where one end will be placed on the front top frame to stand while supporting the lid while it is open. 


You may screw the baton inside the frame and pull it out when you need ventilation for the plants. 

You could use one baton for each lid. Again, it’s up to you how large your cold frame will be and so it will also be up to you how many lids you are going to use. 

Simple cold frame

That’s it!

Now, you can start planting your seedlings!

Or, you may put your small pots inside the cold frame.

Bet u didn’t think making a cold frame is that easy?

By the way

Keep in mind that the above tips were supposing that you are using wood to create the cold frame. 



It’s important to protect the seedlings so that they will grow healthy and beautiful. One way to really do this is to ensconce them in a cold frame while growing up. It’s not just about protecting them from the cold, it’s also about hardening them. 

Don’t waste your money on buying a cold frame, though. You can make it yourself. It’s actually quite easy. Even better–you can actually make one according to what you really need. There will be a personal touch to it. 

So, how to make a cold frame? You can make one from a material that you prefer. It’s really up to you. However, we have some simple steps here that you can follow when you make a cold frame from wood.

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