by Zoë Abram
Early Monday morning temperatures dipped to 31 degrees, so the farm experienced the first frost of the season. Small ice crystals clung to the grass outside the window, and everything looked glazed. And then it warmed up into this beautiful day, and we’ve been out in the fields to assess. When the first frost comes, many of the summer crops die. The cells in their leaves freeze and burst. After the frost, they appear waterlogged, and then they’ll turn brown as they dry. The peppers and eggplant that held on through October are done now. Also dead today is the last of the basil, the okra, and other summer crops. Most of these things we had already stopped harvesting; the biggest effect you might see is less lettuce mix in the share.
This 31 degree night wasn’t that cold, we are hoping that a few things will hang on until temperatures dip into the mid 20s. Some of the greens will keep growing; we’ll put hoops and protective row cover over the baby arugula and mesclun in hopes that they’ll grow a little more despite these colder nights. And we’ve started beds of lettuce mix and spinach in our high tunnels. The greens planted inside are still small but will keep growing slowly because they are protected and kept warmer.
Frost signals an end to some types of vegetable crops, but it brings out better flavor in others. The amount of sugars in the brassicas increase in response to frost. The higher sugar content lowers the freezing point of the plant’s cells, which helps it survive through winter. So the kale, collards, broccoli, bok choi and even turnips will taste sweeter in the coming weeks. Now that the frost has come, we’ll begin to dig the parsnips, which also sweeten because of the cold.
Often in late summer we notice the season changing in slow ways. We harvest fewer pounds of tomatoes than we picked the week before. The weeds start to grow slower and go to seed when they are smaller. But then there are moments in the season like the first frost that suddenly alter many things at once. We woke up Monday morning and the farm was changed. We can all look forward to the sweet harvest of late fall.