Cold Tolerance of Vegetables
Q: My cabbage and lettuce crops are looking great even though we have had colder than normal weather. What range can they stand before being frozen out?
A: It is tough to predict how cold temperatures will affect vegetables. Much depends on how the plants were preconditioned. For example, if broccoli has been growing in warm conditions and temperatures drop below 22 degrees F., it will probably be killed. If these same broccoli plants had experienced cool weather for a week or two, they would probably survive the sudden cold.
The real cold weather champs are beets, Brussels sprouts, carrots, collards, kale, parsley, and spinach. They can tolerate short periods below 20 degrees. Temperatures of 26-31 degrees may burn the foliage but will not kill broccoli, cabbage, cauliflower, chard, lettuce, mustard, onion, radish, and turnip.
Interestingly, purple-leaved varieties of vegetables tolerate cold better than their green-leaved counterparts.