Frost blanket, freeze blanket, row cover, frost protection … whatever you call it … now is the time to pull ‘em out of storage or stock up before we get any real freezing weather or frost.
Photo: Randy Lemmon, Getty Images
The light freeze we experienced in late November and the cool weather forecast for this week make for perfect reminders about frost blanket planning, because once a legitimate freeze is headed for the region, every retail outlet that stocks these products will sell out in a flash. So, act now!
If you’re not familiar with frost blankets, let me explain their value. It’s mainly their ability to create a 5 to 8-degree temperature difference between the outside elements and what’s underneath them. Frost blankets and their cousins are made of fabrics spun from polypropylene material which allows 70% of available light through, and that helps keep heat underneath the fabric on light freeze nights. And unlike plastics and common 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 for your plants to benefit from the use of frost blankets. As the name implies, they are great at protecting against frost damage on mornings when the temperature is slightly above freezing, but moisture and humidity are just right to create a layer of frost.
And while sheets, bedspreads, cardboard boxes and curtain material can help provide several degrees of temperature difference, you have to remove them each day when temperatures get back above freezing - you can’t keep a plant covered for more than two days unless you’re using woven fabric.
As for covering with plastic, that’s never a good idea. First, it’s almost always too thin to provide much more than one or two degrees of difference. And plastic that touches the plant acts like a conduit for the cold – it will be pulled straight into the plant. Plus, since plastic can hold moisture against the plant tissues, it will actually cause more serious freeze damage.
Finally, don’t worry about “wind chill.” You may wonder if the temperature gets down to 29 but the wind chill is 22, what good is a frost blanket’s added 5-6 degrees? Well, unlike human skin, plants are not affected by wind chill.
So, if you’re like me and already have plenty of frost blankets in storage, or if you’ve finally decided to invest in some, pull ‘em out or get to the store and stock up now!