One thing that challenges most gardeners is what to do in cold weather to either start seeds or protect seedlings and plants from freezing. Rather than shut down in the winter months, building an inexpensive cold frame could be a solution. Cold frames gardening will extend your growing season – and who doesn’t want fresh produce on their table in dreary cold weather?
Cold frames are typically unheated. They use solar energy stored within the structure and in the soil during the day to maintain warmer temperatures at night. Generally cold frames have a light-permeable cover like glass, Plexiglas, or greenhouse plastic for the top. The sides can be made of any material that is strong enough to support the cover. Generally cold frames do not have a bottom because they use the soil to maintain heat. If a bottom is built on the cold frame, it is important to have drainage holes in them so that water does not stand.
You may think building a cold frame would be too expensive, but they can be built on the cheap from recycled, reused materials – my favorite way to build. Starting from scratch, cold frames can be constructed using PVC pipes and plastic for an inexpensive cold frame. For larger cold frames, the cost can be a bit higher, but still a good alternative for those who want to start their gardens early or who want to have fresh veggies year round. Take a look at some of the ideas and go get creative this winter and begin exciting cold frames gardening in your back yard. .
A Free and Fast Cold Frame Idea
Kevin Lee Jacobs has been using water bottles as mini-greenhouses and cold frames for almost a decade. To start seeds, these cold frames are almost effortless because you pretty much plant the seeds and forget them. They work great in the coldest climates – even covered in snow, they retain enough heat to protect the seedlings. In warmer climates, such as we have in east Texas, the greenhouses are easy to open up on those days when it suddenly turns 80.
In addition to water jugs, you can use milk jugs or soda bottles. Jacobs provides extensive directions for how to build and use your new cold frame, both indoors and out, with numerous examples of how successful using these mini greenhouses has been.
In addition to having a great way to start seeds early and to protect seedlings from cold extremes, by using your empty water jugs, you are being friendly to the environment.
Biodegradable Cold Frame
Grow Journey offers a unique biodegradable cold frame made out of straw that is actually used for three different purposes throughout the year. They use straw as the sides of the cold frame and then cover the inside with recycled windows.
Grow Journey details how they use the straw as mulch for their blackberries, then feed for their chickens once they no longer need the cold frame. Although they do not recommend this cold frame for below USDA Zone 6, it is a good idea for those who have a plentiful supply of straw and are above Zone 6.
Easy to Build PVC Cold Frame
For beginners or those who do not have tools for woodworking, a small PVC cold frame can be built cheaply. This one has a hinged lid that can be opened in warmer weather as needed.
Complete plans are available for building this little cold frame.
Inexpensive Cold Frame for a Square Foot Garden
This inexpensive cold frame was built to fit over a square toot garden. Hinges on one end allow the gardener to raise the top when it gets warm.
While the blogger does not give detailed instructions on this cold frame, it would be easy to build and he provides enough direction that you would be able to easily replicate this cold frame. With this cold frame over your raised beds, you will be able to extend the growing season in the fall and start your garden early in the spring. More fresh veggies for longer is a good thing.
Empty Water Bottle Cold Frame
Looking for something to do with your empty water bottles? This simple cold frame will keep water bottles out of the landfill and provide a great service to you in extending your gardening season. Washington State University Recycler Composters of Lewis County provide detailed directions for building this cold frame from empty water bottles.
You can adjust the size to fit your needs. In fact, you could even build a whole greenhouse out of empty water bottles. All it takes is initiative, imagination and a lot of empty water bottles.
Simple to Build Plywood Cold Frame
This simple to build cold frame costs a bit more than the previous ones but will last for many years. You might have to replace the plastic on the top, but that will be simple to do.
BHG offers detailed plans for this cold frame that extend your growing season for many years.
Your Imagination is Your Only Limitation
As you can tell from these examples, building a cold frame can be accomplished in a weekend or two at the most. The concept is basically simple – a box with a plastic lid that will hold in warmth and moisture. The ideas and plans listed above should give you a great start on building your own cold frame. You will find that having that cold frames gardening will extend your growing season – in some areas to year round gardening – will be a welcome addition to your table. If you build a cold frame using one of these plans or come up with an idea of your own, then please share your design.