Plant growth has come screeching (almost) to a halt. Lettuces just sit, hardly growing. No wonder, you are no doubt thinking. It’s getting colder and colder outside. I know that, but I’m writing about lettuces in my greenhouse. The issue isn’t lack of heat. It’s lack of light.
For more evidence that light is the issue, look to good vegetable gardens in southern Europe. In that mild climate, harvest from a well-planned vegetable garden continues year ‘round. But year ‘round harvest there takes planning — lack of light also makes for very slow growth over there in these darkest months. Unprotected plants survive because the winter weather never gets that cold over there. (And cool-season vegetables, such as spinach, radish, and turnips, that we plan for sprig or fall, are what do well in Mediterranean winters.)
My garden here in the Hudson Valley, at about the 42nd parallel, experiences winter day …