“With which of your products does one prep the soil for winter crops in a mini greenhouse, type Cold Frame Mini Green House by Juwel (I just got one)? It will face South-East. Any experience growing with this method? Any easy crop recommendations?” Question from Judy of Yarmouth Port, Massachusetts
Answer: Thank you for your questions. I have gardened in a cold frame and observed successful and unsuccessful cold-frame gardening. In your northern garden, I would place the cold frame in a sunny south-facing spot close to your home. The reflective heat from the house will provide some winter protection, and the warm sun will help heat the cold frame. If you can, I would also recommend sinking the cold frame a few inches below the soil level, even though I see that the frame you have purchased has clear sides. Really good cold frames are set below the soil level to better hold heat in winter. On unexpectedly hot fall or winter days, be sure to prop the top open to keep the internal temperature from getting too hot.
As far as soil, I would amend your ground soil at the base of the frame with good compost, like Black Gold Garden Compost Blend, at a 1:2 ratio of soil to mulch. The addition of earthworm castings would also be enriching. The lighter and more fertile your soil, the better your veggies will grow. Adding a layer of compost as a protective mulch would also be helpful. (Click here to learn more about creating the best soil for raised beds.)
It is essential to grow cool-season, frost-resistant crops. These are largely winter greens and root crops. The greens that I recommend include mâche, kale, lettuce, and spinach. The best root crops include winter carrots, radishes, and turnips. Parsley and chives are good herbs to try. (Click the following link to learn more about growing winter root crops and click this link to learn more about growing cool-season greens.)
I hope that this information helps!