In early spring, a coldframe or mini greenhouse is useful starting your plants early or for hardening small plants that were started indoors.
Making a cold frame is relatively easy. If you are lucky you can find a discarded old window on trash day if not you may be able to get one cheap from used construction materials center. If not you make your coldframe from new materials.
First decide how large your Coldframe needs to be.
Measure your window or purchased piece of Plexiglas and create a box out of 2×10 inch lumber that it can rest on. The window should extend past your base about a half inch on all sides to allow water to run off.
Common lumber (non pressure treated) should be used anytime you are working around eatable plants.
Once you have your base made you will need to attach your window by using hinges and a small latch. This will secure your Coldframe against wind and will allow you easy access.
Another product you might want to try is a small green house or plastic grow tunnel.
There are a variety of sizes available or you can make your own from some unused plastic painters tarp. A 10mill tarp should be thick enough to withstand some of the early rains but water buildup can happen if you have a flat area.
It is best to use a tent shape or use preformed hoops stakes that will attach to the ground.
Wind can also be a problem in the spring so you need to make sure to use a good number of staples. Duct tape is also useful.
Overheating can be a real problem once temperatures get above 45F outside. You can purchase a cheap refrigerator thermometer and place it in your cold frame so you can read it with your top closed.
To provide the best light you should face the coldframe so Sun hits it from the South, Southwest.
As average daily temperatures increase you should raise or remove the cover for longer periods of time until your ready to transplant.
Final Note
Remember coldframes and Greenhouses can also be used in the fall to extend your growing season. Not only will they boost temperatures and extend growing times they will offer some protection from the early frosts.
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