Depending on the print date and what part of the country you live in, you are likely getting ready for or have just gone through, your first hard freeze of the year.
People who grow gardens pay particular attention to cold weather events. We know that the first frost is an important date. We understand that the first frost of the season heralds the end of the current growing season. Really freezing weather puts us into another gear – real preparation for what will certainly be impacted, and potentially harmed.
The four “P’s” that we will hear about protecting during really cold weather are “people, pipes, pets, and plants.” Severe cold weather is a big deal and each of those “P’s” deserves prompt attention.
And that first hard freeze likely means an end to the remainder of your vegetables. A buddy of mine named John let me gather as many mustard, kale, and collard greens as I wanted before the harsh freezing weather hit. His garden is rather extensive for him and his wife. I took well over five pounds of greens that I put in my freezer. Looking at his garden, I bet he has a few hundred more pounds of greens.
Another friend, Scott, was asking what would brussels sprouts handle. Michigan Extension says Brussels sprouts can take down to 20 degrees F. Our forecast for Monday, January 15 currently has us at 16 degrees. Not that cold for many to our north, but plenty cold for East Texans.
Earlier this week, I spoke to a gardener, Jill, who said she was still harvesting tomatoes from her garden! It’s true. As of January 9, she still had some tomatoes. Now…she was covering and protecting her tomatoes every time the temperatures got below 45. Think of a large plastic “cloche” and an additional blanket during the cold nights.
Let us look at what really happens when frost covers a plant. When water gets below 32, ice crystals that form inside tender leaves will rupture the cells and, effectively, kill it. Anything from 32 down to 29 degrees is generally considered a light freeze (or frost). Temperatures that dwindle down to the 28 to 25 range are expected to be widely limiting to most vegetation. Only a few native or well-adapted plants will continue to grow with temperatures below 25. In February of 2021 during winter storm Uri, we truly learned what were the toughest plants in our area as the temperature went into the single digits.
So, what can you do to protect your remaining perennial plants that are still thriving? Irrigate and cover.
Irrigate before it freezes. Moist soil can hold four times more heat than dry soil. It will also conduct heat to the soil surface faster than dry soil, aiding in frost prevention. In a university study performed years ago, the air temperature above wet soil was 5 degrees F higher than that above dry soil, and the difference was maintained until 6 a.m. the next morning.
Covering plants with a bed sheet can give you 2 to 5 degrees of protection. The covers can be laid right over the crop or can be supported above the plant material on stakes. The varying degrees of protection lie with whether the cover touches the plant. Any material can be used to cover plants. However, woven fabrics are better insulation than plastics or paper.
Smart gardeners harvested all they could before this harsh winter weather.
Really cold-tolerant plants that can sustain some freezes: Collards, Kale, Kohlrabi, Lettuce, Mustard, Onion (sets and seeds), Potato, Rhubarb, Rutabaga, Spinach, and Turnip. If you want to see what lasts thru the lower 20’s, with some protection you provide, conduct your own experiment and see what happens.
The greens from John’s garden are already blanched and put up in the freezer. I’m interested to see how his greens make it through the freeze… and if he needs anymore help picking them.
