My weather is set to turn on a dime which means I need to be ready for anything. Last week, temperatures were still in the 90s but in about a month, I can expect my first freeze. Should my experience prove true, that first frost will be followed by a few more weeks of fall temperatures without the threat of frost. Even though I have a pretty long growing season, there are always fruits left to ripen on tomatoes or peppers, no matter when that frost comes. Something I'm doing now is getting my frost blankets ready for use.
Bedsheets and buckets work, but...
Most of us know the trick of throwing an old bedsheet or bucket over things to protect them from an early frost and I did that for years before getting more serious and switching to true frost blankets. Sheets are always an option and are good for keeping a light frost off plants by keeping the plant 1-2 degrees warmer than the outside air.
However, If you're trying to keep tomatoes and other warm-season plants happy and ripening for a few more weeks, frost blankets are the way to go. Warm-season plants, like tomatoes and peppers, start getting unhappy when temps dip into the 40s, and especially the 30s, so the warmer you can keep them on that frosty night the better.
Varying thicknesses of frost blankets provide different levels of heat retention with the strongest keeping plants about 10 degrees warmer than the outside air. This is the route I chose. Keeping the plant in the lower 40s, vs lower 30s, prevents or minimizes the stress that can cause a plant to just stop right where it is.
Frost blankets are like spouses, the good ones are hard to find
Order. them. now. I'm tempted to say it again because it's so important to order them weeks in advance.
First of all, we're talking about Mother Nature so who knows when things will actually happen. You can't outsmart her but you can be prepared for her shenanigans.
Secondly, it's hard if not impossible to find good ones in the stores, at least from my experience. They'll have something, but in the southern plains, finding a 10-degree protection frost blanket on a shelf is unlikely. And the quality of what they do carry is questionable.
As frost dates approach across the country the demand soars. They quickly sell out from online vendors or, due to the high demand, can't be delivered in two days even with Prime.
Dewitt makes the best*
Three seasons ago, I ordered my first frost blankets after doing extensive online research and wading through hundreds of online reviews. I settled on Dewitt and have since had my choice of confirmed by some of the best gardeners in Oklahoma.
For most home gardeners, a single 6' wide by 50' long roll like this is enough to cover their plants. For 10 degrees of frost protection, make sure to order the 2.5 oz weight. If you need more than 100' it quickly becomes more cost-effective to order from a source selling 250' lengths, which typically run only slightly more than the price of two of the 50' rolls. Unfortunately, I cannot recommend a supplier because I haven't bought 250' lengths.
*I'm not an affiliate for Dewitt, nor is this a sponsored post. This is my honest to goodness, tried, true and confirmed opinion.
Avoid these mistakes
Don't leave these over plants if temps are set to warm to more than 80 degrees during the day. Not only will they keep the temps another 10+ degrees warmer, there will be some greenhouse effect heating which raises the temps even further. If you work, you might find yourself running home at lunch to pull these off your plants. I do. Some of you are reading this and wondering where on the planet it would go from freezing in the morning to 80 degrees in the afternoon. Oklahoma, that's where.
They cut the amount of light down by 60% so keep this in mind for extended uses, such as in tunnels. Creating low tunnels with frost blankets is an option that many gardeners, especially larger-scale ones, will utilize to extend the growing season. If you're new to the technique, be mindful of the reduction of light when placing the tunnels and when selecting plants. The reduced hours of daylight combined with the reduced amount of light penetration won't support healthy, warm-season plants. This means a spot that is too sunny in the summer is probably perfect for fall/winter.
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