Here in agricultural zone 7 we have a fairly short winter, and I have never gone in for winter gardening. I don’t have a greenhouse, for the simple reason that I have never been able to make up my mind what kind to get or where to put one. By late fall I have a freezer full of summer food, and I spend the long nights by the woodstove, catching up on my reading and deciding what to try next.
This year, though, I decided to try some very low-tech strategies to prolong my season. This came about largely because in September I happened to visit a local nursery for supplies and saw a single lonely six pack of young broccoli plants going begging. It seemed a shame to let them become trash, so I brought them home and planted them with the vague idea that they might winter over. After a little more thought, I ordered a roll of Agribon-19 plant protection fabric, a lightweight nonwoven fabric that conveys about 2 degrees of frost protection. It is 13 feet wide and comes folded double, so I put a double layer over the 10′ row of little plants and held it down with stones and bricks around the edges. I did not use hoops or any other kind of support, just left plenty of room for the little plants to grow. (Please note that you cannot do this with tomatoes, peppers, and other plants that have a “growing point” at the top of the plant. In those cases you have to support the fabric and keep it off the growing tip. But the majority of cold-weather garden plants do just fine this way. ) I watered periodically, but did not pay any other attention to the plants until I noticed small heads of broccoli forming. Then I started checking more regularly. Naturally, because of the cold, the plants grew more slowly and the heads formed more slowly than they would in warm temperatures. This was an advantage. I found that the heads would hold for up to a week before harvesting with no loss of quality.
The heads were unusually tender and sweet. I liked them best just steamed with a little butter or olive oil and salt. Not every plant produced well. Two of the six plants began to form heads, then the infant head “browned out” and died, although the rest of the plant looked healthy. I am not sure if this was a disease or what it was, and hope that maybe one of my knowledgeable readers can clue me in. But I harvested four beautiful heads, and they are continuing to form healthy side shoots, including the two plants that did not form heads. Not a bad return for my minimal effort, with an investment of $2.99 for plants and about $10 worth of frost protection fabric which can be reused.
Two weeks ago, after the encouraging broccoli results, I planted three beds of salad greens, cooking greens, and more broccoli. Two beds are covered with a single layer of the lightweight Agribon-19 and the other with the much heavier Agribon-70, which gives about 8 degrees of frost protection but lets less light through. So far, all the beds have germinated well. I will be reporting on results. I still want a greenhouse, but this is looking good as a cheap way to keep fresh food on the table.
Good candidates for growing this way are lettuces of all kinds, chicory, practically everything in the brassica family including broccoli, kale, and collards, arugula, green onions, green garlic, and who knows what all else. One of the beds that I covered is one where I have let edible weeds go to seed in the past, so I will watch with interest to see if I get an early crop of those too. I have planted some snow peas undercover as well, to see if I get a substantially earlier crop this way. In my climate we have a lot of wind storms in the spring, and just giving some protection from wind might speed them along.
This picture is a cautionary tale: you can see here that before using the lighter cloth, you do need to cut away any old stems etc. that are sticking up, since they can tear the fabric.
Also, because of the decreased light transmission, the plants growing under fabric are essentially hothouse plants and will have to be hardened off to full sun gradually in the spring. I speculate that the more bitter greens such as dandelion would be tastier and less bitter when grown this way, but don’t know for sure yet. I am greatly looking forward to finding out.