DIY Cold Frames and Greenhouses

So, you’ve mapped out your farm space and you’ve got your crops and plants growing well. You’ve figured out how and when to water and how to naturally keep pests away.  You’re also learning how to store and what to do with all your produce. But now it’s winter. Gardening in the winter can seem like a whole new hurdle to overcome. Perhaps you’ve decided to overwinter some of your flowers and trees, but what about all the other crops you’ve been caring for? Is there a way to keep them safe in the winter and possibly even extend the growing season? Yes! DIY Cold frames and greenhouses are some of the best ways to protect your sensitive plants and keep the bounty coming for months after your fall harvest.

The Benefits of Cold Frames

Cold frames are any enclosure covering a plant to keep it from freezing during the winter. Frames not only keep out the cold, but they also keep in the warmth.  They allow plants to grow and thrive even in colder temperatures, thus producing longer. Cold frames are great for plants at risk of freezing or that need a little more protection, such as young seedlings.

Cold frames don’t have to be fancy. They can be as simple as a plastic bottle with the bottom cut off so that it fits over a small plant.   A cold frame can be a large house-type structure that stays in place permanently. Here, we’ll talk about the best DIY options for cold frames and greenhouses that will fit on any homestead.

Types of DIY Cold Frames

Once you know the basics of constructing a cold frame you can make your own.  A cold frame is virtually the same as a greenhouse, just on a smaller scale.  They can be built out of a variety of materials which you probably have on hand somewhere around your property. Read through all the options and get an idea of the theory, and then show us your cold frame and what you’ll be putting inside it! We love to see success stories from our fellow farmers.

Simple Cold Frame – This can be made with plywood and plastic sheeting. Simply construct a square or rectangular shape to place around your plants with a top that has the inside cut out (4’ x 4’ with about a 15” sloped top works well). Instead of wood for the middle of the lid, cover the space with plastic or poly sheeting so that warmth and sun can get in. Lift it off completely on warm days or to water.

PVC Pipe Cold Frame – Instead of using wood, here you’ll construct a frame using PVC pipe. Stick the four sides and base through some plastic sheeting and set around your plants. Make a triangular hinged roof with more sheeting and PVC; the hinge will allow you to lift and lower the lid for aeration and watering. You can reuse the PVC frame/roof and replace the sheeting in further years when it wears out!

Plexiglass Cold Frame – If you want to build something that will last year after year without having to replace the plastic sheeting, think about a cold frame with a Plexiglass lid. This is a bit more expensive, but it will last even longer!

Cold Frames with Self-Opening Lids – If you’re up for a more intensive project, try one that will pay off with a self-opening and closing lid! Make a frame for your plants out of wood and PVC pipe, then construct a lid with plastic sheeting stretching across the top. Insert an automatic vent control, such as a Univent, and adjust your temperature settings so that it opens on warm days and closes as soon as it gets cold again. This will cost you a bit more upfront, but you’ll have peace of mind knowing that you don’t have to worry about your plants overheating in their insulated frame!

Types of DIY Greenhouses

Plastic Bottle Greenhouse – There’s nothing that says “reuse” like this! What a great way to make something good out of plastic bottles. Use wooden dowels or PVC pipe to stand bottles as high and wide as you’d like your greenhouse to be. Connect them onto a wooden frame and make another panel for the top. Use hinges to create a door or lid so you can tend to your plants as needed. If you want the bottle panels to be completely enclosed, you could caulk them with silicone; otherwise, the space between the rows will allow for natural ventilation.

Portable Greenhouse – Greenhouses and cold frames don’t have to take up a ton of space! You can build portable ones with constructed bottoms for seedlings that you’re planning to transfer come spring. Use brick for a bottom layer as it will retain heat from the sun and keep the soil warm. Create a plywood box in your desired size and make a lid of clear, glazed acrylic, which is resistant to ice.

Raised Bed Greenhouse – If you already have raised beds housing your precious plants, you just need to put something on top for cold-weather protection. Make some wooden pillars that are about a foot taller than your bed on the front and about 18” taller on the back (with supports in the middle). Then, construct a hinged lid that you fill with plastic sheeting. You can temporarily attach these to your raised beds to remove in the spring, or you can simply remove the lid so the base of the frame is ready for next year.

Making DIY Cold Frames and Greenhouses Work for You

Every farm, homestead, or backyard garden has its unique needs. Take these ideas and adjust them to work for your space, lifestyle, and the produce and plants that grow best in your climate. If you’re more of a visual learner and want to see this idea in action, check out our YouTube video on building a temporary greenhouse. While you’re there, subscribe to Stoney Creek Farm’s channel for all the best tips, tricks, and adventures that we have to share.