Michigan vegetable crop report – May 22, 2024

Insect pests are emerging amidst ongoing planting.

Tomato plants growing through holes in black plastic.
Plasticulture tomatoes off to a strong start. Photo by Chris Galbraith, MSU Extension.


This week’s forecast includes: 

  • Partly to most sunny, breezy and cooler Wednesday. Isolated showers possible east. Fair and dry Thursday (May 23) and most of Friday. Rain developing west – east late Friday and continuing into Saturday morning. Variably cloudy with scattered showers possible Sunday and Monday. 
  • High temperatures in the upper 60s to low 80s Wednesday, cooling to the 70s Thursday and from the low 70s north to low 80s Friday through this weekend. Low temperatures generally from the mid-40s north to mid-50s south through the weekend. 
  • Normal to above normal daily PET rates expected this week (daily values from 0.14-0.18 inches). 
  • Medium range outlooks generally call for seasonable mean temperatures and precipitation totals through next week. 
  • New long lead outlooks are consistent with earlier outlooks and call for warmer than normal mean temperatures for the upcoming summer. months with no forecast direction on precipitation totals. 

Agritourism survey 

The 2024 National Agritourism Survey is now collecting responses. All agricultural operations that welcome visitors—whether for on-farm direct sales, educational programs, entertainment, farm stays, recreation, special events and more—are invited to complete the survey.  

By participating in this survey, you'll help us pinpoint the types of support farmers like you require—whether it's getting business assistance, developing networks, applying for grants or navigating zoning and liability issues.  

If you have questions about this survey, please contact Claudia Schmidt, Penn State Extension specialist, at cschmidt@psu.edu. 

National Agritourism Support System Survey | Qualtrics Survey 

There are currently 32 responses from Michigan. Let’s get it up to 50! 

Produce Food Safety On-Farm Readiness Reviews 

On May 2, the U.S. Food and Drug Administration (FDA) released their final revisions to the Food Safety Modernization Act Produce Safety Rule Pre-Harvest Agricultural Water Rule. If you are a grower in Michigan, this is a great time to schedule an On-Farm Readiness Review (OFRR). Not only can our team help you assess your on-farm produce safety risks, we can help you assess your water system in light of the updated water rule. If you have already had an OFRR on your farm, no problem, we are happy to come back out to help you assess your water system based on the new parts of the water rule. 

An On-Farm Readiness Review (OFRR) is an opportunity for a grower to walk around their farm with their local conservation district produce safety technician and a produce safety specialist from Michigan State University Extension. These 2-hour educational visits take place during the harvest season and are meant to be casual and low stress. Everything discussed during an OFRR is confidential and focused on ways a grower can reduce their own risks in relation to produce safety. There is no pressure to take our advice either, we are just here to support you in your produce safety efforts!  

Crop updates 


West central Michigan growers harvested big pickings the week following Mother’s Day. We are now past the “big flush” and into more average pickings. Asparagus beetle will continue to be a pest to watch out for. Carbaryl and acetamiprid provide effective control and have a one-day preharvest interval.  

Struggling with perennial weeds in your asparagus? For perennial grasses like quackgrass, herbicides like Select (clethodim) or Fusilade (fluazifop-P) can help. For perennial broadleaves, there are not many options to apply during the harvest season that will not also hurt the crop. The best strategy for managing pernicious perennials like Canada thistle, milkweed, etc. is to apply a systemic herbicide like Roundup after the final picking of the season. Pick all the asparagus, especially thin whips that develop fern, the last time over and then apply herbicide. For quackgrass, experience suggests a fall application of glyphosate can also help; it can be applied after the fern has died in November on a warmer day.  

Brassicas and greens 

Transplants of cabbage, broccoli, cauliflower and brussel sprouts have been going in since early April and continue as weather allows. Scouts in southwest Michigan are trapping diamondback moth and cabbage looper.  

Cabbage maggots feed on roots of brassicas, resulting in stunted plants. However, once the spring peak passes this pest is typically no longer a problem in leafy and heading brassicas. In our experience, any surviving plants grow great the rest of the year, and larger plants can tolerate feeding by cabbage maggots and still be productive. The ghosts of damage past may haunt your fields, but remaining plants and later plantings should be just fine! 

Cabbage Maggot Feeding and Stunted Plants.jpg
Stunted plants as a result of cabbage maggot (left) and evidence of feeding on roots (right). Photos by Chris Galbraith, MSU Extension. 

Carrots and celery 

Aster leafhopper infectivity was high for the time of year in sampled Thumb area and west central fields. Pyrethroid insecticides such as Asana or Mustang Maxx (and others) provide affordable, effective control.  



More and more farms are seeding and transplanting cucumbers, summer squash, winter squash, melons and watermelons. Many farms are holding off on pumpkins until later. Be mindful of planting timing with pumpkins when using plastic mulch because they tend to grow faster and may result in longer powdery mildew foliage management to protect fruit from sunburn. Seedcorn maggots were active last week and have been observed as being particularly problematic in field crops this spring. Check out this MSU Extension article for a quick and recent primer on seedcorn maggot: Everything you need to know about seedcorn maggot. 

Fruiting vegetables 

Field tomatoes, peppers and eggplants are being planted on plastic now and some on bare-ground. Rye windbreaks are proving helpful in some areas where transplanting conditions are good save for high wind. Both wind on its own and wind carrying sand can spell trouble for young transplants.  

Root crops and potatoes 

Potatoes are big enough to be hilled in most places. Hilling over the top of emerged plants creates an artificial preemergence scenario for certain herbicides. Potato leafhoppers are being caught. Colorado potato beetle pressure is high already this spring. 

Cabbage maggots and tunneling have been evident in brassica root crops. In some fields, the maggots have come and gone while in others, larvae are still present. Once they finish feeding, the maggots pupate and turn into a new batch of flies. This means there are periods when you can see tunneling, but no maggots. Currently, degree-day models suggest the spring peak has passed, with the next one upcoming. 

Cabbage maggot in turnips.png
Cabbage maggot tunnels and maggots were present over the last few weeks in brassica root crops like turnips. These are the offspring of the spring generation of flies, which is likely over. Maggots will develop into an early summer generation in the coming weeks.


The first berries are ripening in southern Michigan. Got something munching on the roots? See mole activity? The actual damage may not be from moles because they eat insects. The damage could be due to beetle grubs, and the moles are coming in to eat them. However, mole tunnels may also air-prune root systems in a way that stunts plants too. In order to check for nibbling bugs, it can help to dig healthy plants nearby the crummy-looking ones because the ones showing symptoms of dieback are usually abandoned by grubs and you won’t find much there. This tends to be more of a problem when putting strawberries into an area following a multi-year fallow, hay or cover crop period that includes grasses. 


May 30, 7-8 a.m., Field Crops Virtual Breakfast Series: Wheat Fungicide Recommendations  

May 31, Oakland County Pesticide Applicator Training 

June 6, 7-8 a.m., Field Crops Virtual Breakfast Series: Sprayer Setup 

June 8, 9 a.m.-4 p.m., Soil and Composting Field Day 

June 13, 7-8 a.m., Field Crops Virtual Breakfast Series: Irrigation Management 

June 19, 9 a.m.-1:30 p.m., Food-Grade Grains Field Day 

June 20, 7-8 a.m.,Field Crops Virtual Breakfast Series: Wild Weather for Hay 

June 27, 7-8 a.m., Field Crops Virtual Breakfast Series: Insect Update Beneficials & Corn Borer 

July 11, 7-8 a.m., Field Crops Virtual Breakfast Series: Cercospora for Sugarbeets 

July 18, 7-8 a.m., Field Crops Virtual Breakfast Series: White Mold - Tar Spot Spraying – Will it Pay? 

July 25, 7-8 a.m., Field Crops Virtual Breakfast Series: Hot Topics Q&A Session 

Aug. 1, 7-8 a.m., Field Crops Virtual Breakfast Series: Cover Crops After Wheat 

Aug. 2, 10 a.m.-2 p.m., Organic Inspection Field Day at The North Farm 

Aug. 8, 7-8 a.m., Field Crops Virtual Breakfast Series: MSU Diagnostic Lab Topics 

Aug. 12, Small Farms Conference, Benzonia, MI 

Aug. 15, 7-8 a.m., Field Crops Virtual Breakfast Series: Field Crops Nematode Update 

Aug. 22, 7-8 a.m., Field Crops Virtual Breakfast Series: Lime Recommendations for Field Crops 

Aug. 29, 7-8 a.m., Field Crops Virtual Breakfast Series: Maximizing Wheat Yield Potential 

Sept. 5, 7-8 a.m., Field Crops Virtual Breakfast Series: Drought-Proofing Agriculture with Drainage Water Recycling 

Sept. 12, 7-8 a.m., Field Crops Virtual Breakfast Series: Grain Marketing 

Sept. 19, 7-8 a.m., Field Crops Virtual Breakfast Series: Late Season Weed Control 

This work is supported by the Crop Protection and Pest Management Program [grant no. 2021-70006-35450] from the USDA National Institute of Food and Agriculture. Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the view of the U.S. Department of Agriculture. 


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