We set up a cold frame for the first time last autumn but it didn’t do much for us this winter because we installed it so late in the season. However, it provided us with a place to start our vegetables early. The seeds were sown in March when some days were still hovering around 20ºF here. We were able to pick our first salad of the season in April when temperatures outside were in the mid 30ºF to low 50ºF.
The weather is still unpredictable. Temperatures have been swinging between 70ºF daytime and a low around 40ºF at night. It’s still too cold for many vegetables to germinate outside, but I have sown scallion, Mustard ‘Dragon Tongue’ and Oakleaf lettuce in the plot outside the cold frame and it seems to be taking them a little bit longer to sprout. But I can wait as I still have a lot of vegetables to pick from in the cold frame.
Aside from being able to grow leafy vegetables in the cold frame on an early schedule, I’m also able to use it for strengthening the seedlings. Plenty of sunlight can get through the plastic but not direct sun and it stays warm enough in there to avoid stunting the growth of the seedlings. I have to be careful to open it up during the day when the temperature reaches above 50ºF. It becomes a sauna in there if I don’t open it. Too hot or too cold is never good for growing anything.
This one worked so well that I’m tempted to get a larger one that will cover the entire vegetable plot. Maybe I could go through winter without ever buying salad from a store.