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Cold frames (quick guide to building your own)

Sam the pink-haired Wine Punk, and a neighbor who knows how to block steady, asked me to make a post about cold frame construction. I put mine out a few weeks ago and am still making them. We are still a month away from being able to plant outside, so there is still time for you to try this out. A neighbor a couple of blocks away has had his out much longer and is already harvesting really beautiful spinach. Cold frames allow for extended season growing (more about this  in the fall), potentially letting one grow carrots year round. Cold frames are a lot of fun. You can make really fancy ones like my neighbor Dan:

Or scrappier ones like I made from wood and windows I got out of dumpsters and alleys:

I put mulch and compost around the cold frame to both generate heat and to provide some insulation against colder temperatures. I have plans to make a much hardier system this fall complete with walls insulated with packaging styrofoam.

Here are some more of our cold frames:

Salad greens, collards, kale and mustard greens

And here is an even scrappier design for a planter:

Planter in front of the Harvest House on Washington in Urbana

I really like this design as it suggests a really easy way of making a planter with out the need to have access to a lot of tools or basic wood working skills. It looks as if the wood was found and fitted together to make the planter. It could easily be made into a cold frame by placing windows on top or by stretching clear plastic over it.

Here is what you need to make a basic cold frame:

Window found in alley, wood pulled from a dumpster

I cut the boards with a power saw (a hand held saw works just as well) to the same lengths as the sides of the windows making sure to cut two of the sides a little smaller in relation to the thickness of the other boards.

Assembled frame

I affixed the pieces of wood together with wood glue (which really helps keep the wood together as it will be on, and holding, wet, moist ground) and screws (long nails will work too).

Frame placed, filled with soil

Next, find a location for your cold frame. I put soil in mine after digging up the grass underneath. The soil in our yard is poor. We have not spent the time and effort to get the soil in this spot in good condition for growing healthy plants. You might want to consider putting good top soil into your frame if you have a similar situation.

Carrots planted. Window placed.

The final steps are to plant the cold frame – I put carrots in this one – and water the seeds, finally placing the window on top of the frame

You can see the cold frame in action within just a few minutes; condensation starts to appear on the underside of the window.

Tags: backyard gardening, cold frames, extended season growing