The Benefits of Garden Cold Frames

There are many benefits of garden cold frames, and things like lettuces grow beautifully in cold frames. Here is why you need one, or two for your garden.

Here in the northeast, we’re still 2-3 weeks out of being able to plant our vegetable gardens in the ground. We’re not out of the clear of freezing nights until around Mother’s Day. Still, that doesn’t mean that you can’t plant outside; you just need to do so wisely, by using a cold frame. This is why it is such a huge benefit to garden with cold frames.

Cold frames, usually a wooden box with a recycled window, shower door or plastic over the top. It’s a great way to extend the growing season, and harvest more vegetables. A simple structure, it uses solar energy and insulation to provide a microclimate for your garden. Not to get all science-y on you, but let’s just say that these frames definitely help the garden grow, and let you grow things early in the spring and later in to the fall. Winter too, in some climates that aren’t so harsh.

So I set out to build my own. I used scrap ply wood that I had on hand, measured out the size that I wanted to build, and used my table saw to make the cuts. I found some small windows on the Hudson Valley Yard Sale page, perfect for the top of the frames, attaching each with simple hinges. No bottom is necessary for cold frames, and I have removed the bottom that I did put on mine. Reason being, whether plants are sowed in pots or directly in the soil, this will eliminate transplanting shock and will better acclimate to the outset.

Relatively inexpensive to build, the cost really boils down to the window, if you even choose to use a window or some heavy duty plastic. Craigslist and Facebook Marketplace are your best bet to find a window bargain, that is, if you don’t have a spare lying around. The sheathing plywood can be found at Home Depot for $14 – $30 for a 4’x8’ sheet. Heavy duty plastic can be found in the paint section.

I have found gardening with cold frames actually makes gardening easier. Exactly what the experts say. I’m very careful not to overwater, and during the day when there’s no heavy wind, temps are over 50 and the sun is out, I vent open the cold frames to bring air circulation to my precious plants. I use a scrap piece of 2 by 4 wood to hold the frame open just enough, about 4 inches or so. An important cold frame tip: keep in mind that more plants die of excessive heat and drought in cold frames than from cold damage. Proper ventilation is very important. At night, close the frame to protect the plants from the cold, and possibly windy nights.   Once the weather is free of any dangers of frost, I will transplant my plants into their designated bed in my garden.

Not in the mood to build your own cold frame, but want to garden with one? Here is an affordable one that I recommend. 

What’s even better, is that I’ll benefit from these cold frames three seasons of the year. I’ll be able to plant and harvest heartier vegetables late into the fall, and for my more tender plants that need to be protected from the winter, I’ll store in these cold frames offering much needed protection from the harsh elements of that season.

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