The last couple of weeks I’ve been working on a project to replace the cold frames I have behind our greenhouse. I’ve got three growing areas back there with about 50 square feet of growing space, and the cold frames provide protection from wind and critters like deer and rabbits. The frames have been falling apart for some time, and I finally decided it was time to replace them. Here’s what they looked like back in the fall of 2020, when they were still in fairly good shape.
back side of greenhouse
And here’s what they look like now, falling apart on the tops and bottoms with mostly rotten wood. This is a photo of one I moved to make room for the new ones, which I decided to buy instead of make.
rotting cold frame
The first step was to get rid of the old cold frame pieces, and put down cardboard around the edges to keep down weeds. Then I could assemble the new beds and move them into place. Finally I covered the cardboard with cypress mulch, and then started planting. I am continuing to use one old cold frame bottom, which will be planted with annual and perennial herbs. That bed does not need to be covered or protected, so the top isn’t really necessary and the bottom itself isn’t really that important.
assembling the beds
The old cold frames were made from untreated pine boards, and only lasted a few years before starting to decay. The new ones are made from white cedar, and with any luck should last as long as I do! They are a bit pricey up front, but given the cost of lumber and the hardware it takes to assemble the frames I thought it would be money well spent in the long run. These assemble with slots and pegs, and can be stacked to provide more growing room. I’ve got two of the 4×4 foot beds stacked together in one bed, and I planted curly kale (Winterbor, Starbor) in there and interplanted with onions. I plan to pull the onions as spring onions/scallions.
new cedar beds
In the third bed, I have a 4×6 foot cedar bed that I just planted yesterday with kohlrabi and lettuce seedlings. I also interplanted these with onions to fill in the spaces between rows. I sprinkled Sluggo Plus around the plants, then covered with the bird netting material.
bed after planting lettuce, kohlrabi and onions
I’ll share more updates as the growing season progresses, but so far I am pleased with the makeover results. I’ll be back soon with more happenings from Happy Acres!
Excellent explanation of your cold frames. How much earlier do you think you plant with them? Thanks for sharing this.
Thanks! The cold frames let me plant a few weeks earlier, and if I covered with a row cover material like Agribon I could plant a bit earlier.
I have cold frames. I love them. I can harvest greens, argula and lettuce quite late depending on when the below zero farenheit weather comes. I also can sow greens, arugula, lettuce, and spinach in fall that comes up much earlier in spring. I stacked bricks behind the north wall of one cold frames and that one stays a bit warmer. The only bad part is having to vent them when it’s sunny and 40F so the plants don’t get too hot. Also it can get quite windy here so I have to weight the cold frame lids down when venting them so they don’t blow away.
I used cold frames for years before I got the greenhouse. They are quite useful to extend the harvest. I did have one blow away during a storm and land at least 100 feet away!
Dave – your post has inspired me to add a cold frame to extend the season! I took a look at the post from 2011 and your frames were 8″ in front & 12.5″ in back. Are the new ones the same? (they seem to look the same height all around in the pics) Also, do you have them facing south? TY!
Interesting post. I haven’t had to use cold frames/greenhouses in Sydney, Australia, but we also don’t get snow (only frost). I am also a slightly lazy gardener.