The University of Nebraska-Lincoln Extension Office says some crops will need to be harvested before a frost, while others can withstand colder temperatures.
Warm weather crops that do not tolerate frost and low temperatures include tomatoes, peppers, sweet potatoes, cucumbers and summer squash. Watermelon, pumpkin and corn also are sensitive to cool temperatures and can result in plant damage or death.
Crops that withstand a light frost between down to 30 degrees include beets, mustard, Chinese cabbage, radishes, collards, spinach, potatoes, Swiss chard, Bibb lettuce, green onions and leaf lettuce.
Crops that can withstand several freezes include cabbage, carrots, broccoli, cauliflower, rutabagas, Brussels sprouts, and kale.