Building a Cold Frame with Blocks

Build A Cold Frame With Blocks

Cold frames are used in countries where the season is changing constantly. A cold frame helps gardeners to start planting quicker in spring. A cold frame is also used to let and leave plants to grow well, especially plants that tend to need the cool season to grow. A cold frame basically is a box with a clear and safe cover that is able to open and close well. A clear cover is needed to allow the sun to shine through it in order to enable the plants to gain the right amount of sunlight. In warmer days, the cover is slightly lifted so as to let out hot air, which will not suffocate the plants. Plants are put inside the cold frame and there are some gardeners who prefer theirs planted into the soil in the frame.

There are many ways to build a cold frame which functions to lengthen your growing season. Most people would build a cold frame out of wood with a clear cover that opens and closes. If you want to have a permanent cold frame in your garden, then you can use concrete blocks as these materials could sustain better than wood during winter season. There are many types of blocks that can be used for the cold frame such as cement or concrete. Here are the steps on how to build a cold frame with blocks.

You will need:

Concrete blocks





First, remove the top 8 inches of soil in a 6 by 3 foot area. Pick an area that will be in full sun view in early spring and winter. At the same time, the place should be near your home so that you can access the cold frame easily during a bad weather.

Then, place the concrete blocks just inside the perimeter of the excavated area to create the cold frame wall. If applicable, lace the blocks so that the holes in the center of the blocks face upward. To make sure that they are touching each other, set the blocks in side by side position.

Place a second row of blocks on top of the first row so they overlap the seam where two blocks meet in the first row. Drive a wood stake through the holes in the corner blocks to help anchor them if you are using blocks that have holes in the center.

Next, put the removed soil back into the cold frame box. Add any of your desired planting materials such as compost or fertilizer, if you are planting directly from the soil. To protect the cold frame from strong winds, set a sheet of clear glass or plastic sheet over the top of the cold frame. Place bricks or blocks of wood between the glass and the cold frame blocks to help the glass to open on warm days.

Image Credit:

Flickr CC

Additional Reading:

Building & Using Cold Frames: Garden Way Publishing Bulletin A-39

The Complete Greenhouse Book: Building and Using Greenhouses from Cold-Frames to Solar Structures