First frost. Kind of. It’s a matter of degrees. There are hundreds of variables that affect whether a crop gets frosted. Elevation, wind, sugar content, overall plant health, the plant’s height off the ground, surrounding topography — these are just of few of the obvious ones. There’s also something to be said for the natural heat that a healthy soil generates, as all of its billions of organisms move and breathe and transact their business. That becomes increasingly obvious as the soil begins to freeze. On the cherry tomatoes — all in a neat line — some got frozen, but most didn’t. I can’t say why. On the sweet peppers, a flimsy sheet of agricultural cloth made the difference. They all look perfect. Low-lying crops like squash got completely whacked. It looks likes a spidery hand raked down the field, grabbing this, but not that. The pattern is not obvious to me and I spent a long time studying it today, in between rounds of spreading manure for next year’s crops with the horses. Load, spread, sweat, pause, think, repeat.
Most remarkable, of course, is the overwhelming number of plants that don’t freeze at freezing temperatures. It is mind-boggling, if I allow myself to dwell on it for a moment. Everything in the carrot family and the cabbage family especially, have all these sleights of hand they use to outwit the undeniable fact that water freezes at 32 degrees. They use two tricks, mainly. They increase their sugar content, which prevents ice from forming; or they make inter-cellular spaces that allow ice to form without damaging cell walls. If you think of the mechanics, it’s miraculous. It’s like making an anti-gravity machine; it defies physical laws. It shouldn’t be possible, and yet we witness it in most native plants. If vegetables weren’t mainly of tropical origin, we wouldn’t notice first frost at all. Certainly pasture plants don’t care. They all use these tricks.
I’ve noticed that the horses will preferentially graze portions of the pasture that have gotten frosted — I imagine because those grasses produce more sugar. It’s certainly true of our hardy crops. Carrots, beets, cabbage, kale, lettuce — they all sweeten after each consecutive frost. We never harvest these crops for the winter until they’ve experienced a few hard frosts because the flavor improves so dramatically. In my mind, it helps compensate for the frost-sensitive crops that leave the table; the green beans may be gone, but damn those carrots are good now.
One of the things I’ll enjoy most in the coming weeks is watching the woods color and then brown, while the cold-hardy crops and the pasture grasses stay green. We didn’t plant much rye cover crop this year, but we always plant some, partly just because it stays green longer than almost any other cultivated plant — it’s bright green until it gets covered by snow (and even then it’s green, though we can’t see it). Long after everything else has succumbed, rye persists as a reminder of the riot of growth that has just passed and that will come again. (Ruthie’s middle name is Rye. It’s a happy, hardy, vibrant plant. What more can we hope for our children?)
At the farm, the frost was patchy; at my folks’ place, on Capen Street, we had four consecutive nights of real and total frost. The field is in a low pocket, down on the river where cold flows in from the surrounding hills and gets stuck. The vegetables there were all harvested long ago —the sandy soil is perfect for early plantings, and that’s where your early lettuce, peas, carrots, beets, herbs, and onions came from. All that’s left there now is CBD hemp, which we plant there because the State won’t let you plant hemp on APR land (which is our entire farm). The hemp got nailed — all the leaves are dead and brown, though the flowers still look amazing. First frost for hemp means the clock starts ticking on mold, which takes hold as the plants weaken. This dry weather though, unusual for this time of year, has been working in our favor, and we’re nearly done harvesting this year’s lovely, smelly, sticky flowers for processing into oil. (You can get Sawyer Farm CBD from the farm store on at www.sawyerfarmcbd.com.)
I like the otherwise invisible variations that first frost reveals. For a grower, it’s a series of clues about the apparently minor differences that go into producing a bountiful, healthy crop. “32 degrees” seems like a firm, true thing. The freeze is coming, for sure. All the water in the plants and in the top few feet of soil of soil will freeze this winter. That is certain. But when and how involves so much more than the weather. Our management and the plants’ will to survive makes that simple truth complicated and interesting.
Meanwhile, this streak of warmer weather is great and I’m not complaining about above-freezing lows in the ten-day forecast!
A couple answers to first-frost questions that I’ve gotten this week:
1) Do I need to harvest my beets? (Cabbage? Carrots?). NO! Wait a while. You will notice dead/dying/diseased tops long before the plant needs to be pulled. Assuming you’re storing in your basement, waiting until your basement is colder is more important than any potential frost damage. In general, these crops want to be pulled before the ground freezes, but not much sooner…
2) Do I need to harvest my onions? Yes. Even a light freeze will damage their outer layer of skin, which will soon lead to rot.
3) Is it time to harvest winter squash? Winter squash seems to handle temperatures down into the high 20s. It does not want to actually freeze, but as a large thing that holds some heat, it won’t be affected by light frosts. Best to wait until the stem is dry and brown and the fruit snaps off if possible.
4) Can I still eat _______ if the plant got frosted? Taste it!
5) Can I harvest ______ while it’s frozen? No. Unless it’s kale, let it defrost and resume its normal physiological activity before harvesting.
6) Is freezing OK for dry beans, shelling corn, grains, etc? Yes. I know of no low temperatures that will degrade the quality of a seed.
7) Is it too late to plant a cover crop? Kind of. It’s not too late for rye, but rye is a persistent beast in the spring. You won’t want it growing anywhere you’re hoping to plant anything before mid-June. If you can afford to let it flower and set seed, it can be killed easily by mowing/scything. For late-planted crops, like storage cabbage and carrots, this timing can work well. If you wait until the ground starts to freeze, you can sow clover. It will sprout first thing in spring and make a nice ground cover by June. If you intend to plant something in that spot in spring, though, it’s a waste of time and money. However, we’re doing lots of experiments involving planting directly into an established WHITE clover cover crop. There’s some info on our instagram (@sawyerfarm), and I’d love to talk about it if you’re interested.
One thought on “A Matter of Degrees”
Good info! Thanks.