How to cover plants in winter?
We have relatively mild winters in Central Texas, so most plants don’t need to be protected. But if we have an unusually harsh winter, or if you have a few tender plants in your garden, you may need to do a little extra work.
First, don’t use plastic directly over plants (a greenhouse/patio situation is fine). It traps too much moisture, might actually decrease the temperature, and could end up doing more harm than good.
Specially-designed frost protection cloth is best, of course, and if you live in colder parts of the nation, you might need to leave it on for several days or longer, so it would be a good investment.
But here in Central Texas, the temperatures are rarely in the danger zone for more than a day or two, so temporary blankets or old sheets will usually suffice. In fact, if your plants are small enough, you can even use a bucket.
Whatever you use, the key is to make sure it reaches all the way to the ground, to the point that no air can sneak in underneath it. With a bucket, you might place a rock or brick on top, to make sure it doesn’t blow off.
If you’re using fabric thrown over your plant, make sure it’s long enough to drape onto the ground. Then, weigh the ends down with bricks or rocks, so it doesn’t blow around. It’s logical to think about protecting the upper plant parts from frosty air and cold winds, but you also need to protect the soil. Soil holds moisture and warmth, which will radiate up around your plant, increasing the temperature slightly, so enclosing a bit of ground in your protection zone is critical.