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Customize a Cold Frame for a Garden
© Stephie McCarthy
Video coming soon!
The cold frame kit shown above was easy to put together — and easy to modify to make it a true gardener's dream. We've added links to two other cold frame kits we love at the bottom of this post.
With easy updates, this cold frame kit is already providing treats for the kitchen.
We added a base and much more, using recycled materials.
We're already growing cold-hardy broccoli, kale, lettuce, spinach, peas, broccoli raab, red cabbage, and dianthus flowers (the petals are edible—not the greens).
Our first step was to caulk to every seam between wood and plastic to keep out bugs and mold which can cause unsightly webs and green spots.
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We used clear silicone caulk, smoothing it with a wet fingertip into the cracks. It dried off-white instead of clear, but it will go a long way keeping the panels clean.
When dry, we assembled the four sides and the top.
Holes for screws were pre-drilled making the kit very easy to put together. We put some pieces together upside down at first, but that was easily fixed.
Wing nuts on the sides can be kept a bit loose for opening or closing. You can also tighten down the lid in case of animals or wind.
We placed the cold frame on top of a simple base made from recycled 1.5" x 8" lumber.
The cold frame is slightly larger than the base. We used 1" x 3" and 1" x 1"trim to create supports on sides and front, outside, and on the sides, inside. We can detach the cold frame, but it will not blow away in a high wind.
We've highlighted in pink above how the trim holds the cold frame in place. Our frame can be removed, but if you live in an area with high wind, you may want to attach your cold frame to the base.
Here's how we customized the inside of the box with sand, foam, and rubber. Shown above is: a) sand on the pavement to repel slugs and mold beneath the box; b) wire fencing on top to repel cats and squirrels; c) recycled foam lining for warmth; d) prop to hold up the lid
Thin recycled packing foam was cut to fit the base on each side and the bottom for insulation.
A piece of rubber from a recycled air mattress makes great waterproof lining material. We used black tacks to attach around the edges inside.
The black lining also helps retain heat and keeps cold air and bugs from creeping in from below.
The rubber lining is easy to clean and holds water for thirsty roots between watering.
Closing the lid helps retain humidity and raises the interior temperature about 10 degrees. Be sure to open the lid whenever the temperatures go about 65° F or so.
The base will age well with a blend of green and brown paint mixed with our favorite waterproofing finish by BEHR.
A cat sitting on top of thin polycarbonate will crush or warp the lid permanently …
… but, a piece of wire fencing bent to fit onto the lid deters cats from walking or sleeping on the top.
We'll trim this recycled blanket to fit for extra insulation on frigid nights. The wire will help hold it in place.
There are endless ways to use cuttings from a box like this.
This was our first harvest from the customized cold frame.
Be sure to keep a cold frame lid propped open on warm days because the temperature rises quickly in the sun.
Here are two morewood and polycarbonate kits for gardeners you may like:
Garden and Porch Decor
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