Weekly Crop Update Frost Cover Storage

By Scout Nelson

The latest Minnesota vegetable update focuses on making the most of a warmer September forecast and preparing for the fall season. NOAA predicts a warmer than average month, though frosts may still arrive at typical times. Growers are reminded to use frost blankets or row covers and, in some cases, irrigation to protect sensitive crops from light frost.

The update also emphasizes fall cover crops. Early September is ideal for planting oats and peas, which fix nitrogen and suppress weeds before dying off in winter. For later plantings into October, mixes like winter rye or winter wheat with hairy vetch help protect soil, prevent erosion, and improve fertility for later crops. Growers in high tunnels are encouraged to join a cover crop trial offering free seed and surveys through November.

Storage season is also here, making it a good time to revisit postharvest handling practices and proper storage conditions for vegetables.

Crop-specific notes include:

• Brussels sprouts: Topping in early September can improve yields and create a more uniform harvest, though timing is key as sprouts remain susceptible to freezing damage below 14°F.
• Carrots: Excess rainfall has caused wet soil conditions, raising the risk of bacterial soft rot. Diagnosis is encouraged through plant clinics due to disease complexity.
• Cucumbers: Plants are slowing down as cooler weather arrives.
• Basil: End-of-season decline, and downy mildew are common. Postharvest handling is crucial, with recommendations to avoid cold stress and handle leaves gently.
• Tomatoes: Foliar diseases like early blight have increased, and topping is an option, though some growers prefer harvesting all fruit, including green tomatoes, late in the season.
• Zucchini: Powdery mildew is spreading, and many plantings are reaching the end of their cycle, with some vine borer damage reported.

This week’s update highlights practical steps to manage fall transitions in vegetable production while preparing for harvest and storage challenges.

Photo Credit:gettyimages-zbynek-pospisil