Weekly vegetable update 6/29/22

Author: Natalie Hoidal, UMN Extension educator, local foods and vegetable crops 

This week our team visited farms along the North Shore, as well as in the Twin Cities and the Brainerd area. Crops are at totally different stages across the state; tomatoes are still less than 1 foot tall along the North Shore, while they are already setting fruit elsewhere. Growers in Northern Minnesota reported being anywhere from 3-6 weeks behind their typical schedules due to cool temperatures and excessive rainfall, while growers in the south are experiencing excessive heat and very little rain.

Crop updates

• Tomatoes: While a couple of farms have ripe tomatoes, most people are at the stage of waiting patiently for their green tomatoes (in tunnels) to ripen.

• Peppers: Peppers are generally doing well, despite some of the odd looking plants I talked about last week. There are a couple of issues starting to emerge: we've seen some sunburn on exposed peppers, particularly in tunnels. As the canopy develops, it should shade the growing fruit, but the first fruits can easily burn when they are exposed to sunlight. It's best to remove fruit with sunburn / sunscald as quickly as possible, as they can be susceptible to secondary infections. Additionally, we're starting to see more aphids in tunnels. Aphids can be removed manually, or with insecticides. Check the Midwest veg guide for insecticide options, and make sure to scout regularly, as aphids often stay on the undersides of the leaves.
  

Photo: Hannah Walsh

Photo: Bonsa Mohamed

• Garlic: We had a reality check this week about how far behind growers in Northern Minnesota are at this point. While growers in southern Minnesota have been removing scapes for a couple of weeks, scapes have not even begun to develop in the north, at least along Lake Superior. 

Photo: Natalie Hoidal

• Potatoes: Many potato fields are flowering this week. We saw potato beetles at all four larval stages this week near Brainerd; as potato beetles reach the larger larval stages, treatment becomes less effective. Continue to focus on maintaining soil moisture through irrigation and other practices like using straw mulch.

All 4 larval stages of CPB, Photo: Natalie Hoidal

• Cole crops:  I'm seeing a lot of heat stress and sunscald on recently transplanted broccoli and other Brassica crops. The sun is a lot stronger than it was in early May, so make sure you're taking extra care to harden off your final successions of cole crops. I haven't seen any black rot or Alternaria yet, but our colleagues in Ontario are seeing black rot across the region. 
  

• Cucurbits: Cucumber beetles are officially here! We saw them across most of the state last week. Kaolin clay and trap crops are good first lines of defense, but make sure you're scouting regularly to monitor populations as they increase. Zucchini season is here in Southern Minnesota. Most of the zucchini plants in northern Minnesota were still quite small this week unless they were in a tunnel. As cucumbers start to come in, don't be alarmed by curvy looking fruit. This is a sign of poor pollination, which is common during hot weather.
  

Photo: Natalie Hoidal

Problems in the field / things to do this week

Is it worth re-planting?

Growers along Lake Superior reported being up to 6 weeks behind this year compared to recent years. We saw folks transplanting small tomatoes this week that might not fruit before the first frost. In other places, growers are replanting pumpkins, beans, and other large seeded crops due to bird, seedcorn maggot, and gopher feeding. Fall feels far away right now, but if you have to re-plant, make sure you're calculating the days left until the first frost. This is especially important for frost sensitive crops. You can check the frost probabilities for your area with the DNR's Final Spring / First Fall Freeze Data Probabilities tool.

 

Connect with the fruit & vegetable team

If you're seeing interesting things in your fields, need help identifying problems, or just want to share photos, we'd love to hear from you! Growers can reach out directly to me any time at hoida016@umn.edu, and you can submit questions and diagnostic help below.