When we decided to build a cold frame last year, I did some reading up on the subject to try to learn the dos and don’ts of growing in a cold frame.
Now that we’ve planted a few things inside, I can say I have learned a few things first hand.
The most important lesson is to ventilate. Everything I read said it is better to ventilate too much and have the frame a little cool, then to let it get hot inside. I have been amazed at how hot our cold frame has been, even on seemingly cloudy, cold days. I went out one day on a very gray, cloudy day, and the inside temperature was 135 degrees (F)!! Wow! The lid now stays partially open all the time, and the temperature has still been over 100 some days. Needless to say, the lettuce we planted in early spring has wilted and died. It is a cool weather crop and 100 degrees doesn’t work as cool weather 🙂 There are some onions planted though, which I hope will come up eventually.
The other lesson is to not underestimate how much heat the frame can create. As I said before, I’ve been amazed at how hot our frame has been. I did not anticipate how hot it would get inside, even with reading books on the subject. Whether the day is overcast, windy, or whatever, you need to check the temperature inside to make sure your plants are not getting overheated.
My new plan is to try to sprout some herbs in pots inside. Seeds need a warm, sunny location to grow, and I think it will be the perfect spot to make that happen.
