Tuesday, February 15, 2011

Cold Frames......observations

The cold frames are doing very well maintaining a good temperature. The lowest temperature that has been recorded is 27 F at night when the temperatures outside were in the single digits at night and only in the teens during the day for a few days..that's pretty good! The cold frames face south and do not have many elements creating much shade on them. On a bright sunny day when the temperature outside only reaches the 20's, I have to open them up to let in some cool air. I really have to pay attention when the sun is shining or they will climb to 70 F or higher in no time at all. I really don't want the temperatures to fluctuate too much and stress the plants.

Cold Frame Lettuce

When the cold frames are covered with snow, they usually stay around 37 F all day and all night. I think that this makes for happy plants. The temperatures over the next week are supposed to climb in to the mid 50's!! The higher temperatures in conjunction with the extended day light hours will hopefully get those veggies growing!! This year I will definitely get my winter vegetables planted on time and not in November!!

A radish showing a little red and some Arugala

I am not sure how much heat the rope lights are adding to the overall temperature inside the cold frames. I did however check the soil temperature on Saturday and it was about 45-47 F. The remainder of the garden beds are still covered with a significant amount of snow....so, you know the ground is quite cold.

A little more lettuce

Another observation that I have made is that a few plants in the cold frame on the left had some insect damage and there was little damage in the other cold frame. I had added some diatomaceous earth a while back and the munching has seemed to stop.

The Pak Choi that the insects must like as much as we do! The picture on the left is from the one cold frame and the picture on the right is from the other cold frame.


  1. I have the worst time with pac choy in my greenhouse too. It is the number 1 bug eaten veg. I reapply the DE everytime I water and it has helped. I also notice when it gets above 40 in the greenhouse the bugs defrost too. Aphids are another one that seem to live through everything.

  2. Jane, I guess that I should add some more DE. It was a while ago that I added it. I'm never quite sure how often it should be added to the soil

  3. If my hoop house was closer to the house, I would totally try those rope lights. It's amazing how much residual heat is generated from them.

  4. I would say that overall the little hoop house that could has been a success this winter. I have a different idea for next winter. I want to have a growing area in my basement for cool weather plants. Nothing like a few radishes and a plate of lettuce for winter munching. It is experimental growing for sure but hopefully with fluorescent lighting, it will be successful. It is another phase of the food storage area of the basement.

    Have a great pre spring time garden planning day.

  5. Maintaining those temps in your coldframe is very good, and you're definitely doing well with it...

  6. Living in California, near the beach, I have never had to use a cold box. When I look at pictures from others I always get the feeling that it is like having a treasure box in your yard with all kinds of miraculous things taking place inside...despite the external elements! It is a good model for how to approach life...just stay in your cold box and do your thing! :-)

  7. Thomas, The rope lights seem to be working well and I haven't noticed a change in the electric bill...so that's good!

    David, I like the idea of growing some plants in the basement. Maybe I will try to keep some fresh lettuce growing down there next year.

    EG, I am very pleased with the cold frames so far. I think that things would have been much better if I started the plants at the correct time.

  8. Your veggies look very happy in there!

  9. It is so important to keep balanced temperature in the cold frame. I see that you are doing a great job. Soon it will get warmer so hopefully you will be able to keep it open all the time.
    My greenhouse is now constantly open, we get nights about freezing level and days are a bit warmer.


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