Frost blanket, freeze blanket, row cover, frost protection … whatever you call them, now is the time to stock up on them before we get freezing weather or frost.
Or, if you’re like me, pull them out of storage.
The cold front that blew through this week is the perfect reminder that you’ll need them when a legitimate freeze is forecast for the region. Every retail outlet that stocks them will sell out in a flash. So, act now!
If you’re not familiar with frost blankets, they have the unique ability to create a 5- or 6-degree (or better) difference between the elements and what’s underneath them. Frost blankets and their cousins are made of spun polypropylene material that can allow 70 percent of available light to pass through, which helps to keep heat underneath the fabric on light-freeze nights. And unlike plastics and household blankets, these fabrics allow air and moisture to percolate down to the ground around the plants.
Temperatures don’t have to be freezing or below to benefit from using frost blankets. As their name implies, they are great at protecting on those mornings when temperatures are slightly above freezing, but the humidity is just right to create a layer of frost.
Although sheets, bedspreads, cardboard boxes and curtain material can help provide several degrees of temperature difference, they must be removed each day when the temps rise back above freezing – plants can’t be covered for more than two days, unless by woven fabric.
And remember that covering with plastic is never a good idea. First, it’s almost always too thin to provide much difference in temperatures. And any plastic that touches the plant acts like a conduit, allowing the freezing weather to be pulled straight in. In fact, where plastic holds moisture against the plant tissues, it actually causes more serious freeze damage.
Finally, don’t worry about “wind chill.” If the temperature gets down to 29, but the wind chill is 22, you may wonder about the value of a frost blanket that could only keep temperatures below it five or six degrees warmer. Well, unlike human skin, wind chill has no effect on plants.