Frost blanket. Freeze blanket. Row cover. Frost protection. Whatever you call them, now is the time to stock up on them - before we actually get freezing weather or a frost. Or pull them out of storage, if you’ve already got some, like me.
The early, light freeze we experienced in November, and some cooler weather expected soon, are good reminders to stock up on frost blankets. While no actual freeze is currently forecast for this area, once one is predicted, every retail outlet that sells such products will be sold out in a flash. So, act now!
If you’re not familiar with frost blankets, let me explain why you should get some. It is mainly their unique ability to create a 5- to 6-degree temperature difference between the elements and what’s underneath. Sometimes, it can even be a difference of 6-8 degrees. Because frost blankets are made from spun polypropylene material that allows 70 percent of the available light through, a certain amount of daytime heat remains underneath the fabric on light freeze nights. Plus, unlike plastics and bed sheets, these fabrics allow air and moisture to percolate down to the ground around the plants.
And temperatures don’t have to be freezing or below to benefit from the use of frost blankets. As the name suggests, they are great at protecting against frost damage on mornings when the temperatures are slightly above freezing but the moisture and humidity are just right to create a layer of frost.
While sheets, bedspreads, cardboard boxes and curtain material can help provide several degrees of temperature difference, they must be removed each day as the temperatures get back above freezing. A plant should not be covered for more than two days, unless with woven-fabric style protection.
And if you’re still covering things with plastic, that’s never a good idea. First, it’s almost always too thin to provide much more than a 1- or 2-degree difference in temperatures. And any plastic that actually touches the plant acts like a conduit for the freezing temperatures – the cold is actually pulled straight into the plant. And since plastic can hold moisture against the plant tissues, it can cause more serious freeze damage.
By the way … ignore “wind chill” when it comes to your plants. If the temperature gets down to 29, and the wind chill is 22, you may perceive the 5- to 6-degree difference. But, “wind chill” has no effect on vegetation.
So, if you’re like me with plenty of frost blankets in storage, pull ‘em out and get ‘em ready. But if you’re without any and have decided to invest in some, get to the store and stock up. Now!