Southeast Michigan vegetable update – April 24, 2019

Compared to last spring, a lot of fieldwork and planting has been done.

Bacterial canker on tomato leaf
Bacterial diseases of tomatoes, like bacterial canker (pictured), can start in the greenhouse. Photo by Zach Hansen, University of Tennessee.


This spring has been warm and productive compared to last year, but much of the state is still behind normal degree day-wise (though the area around Lenawee and Monroe County border is not). This last week brought with it some soaking rains, and the next chance of rain is early next week. Long-term weather models suggest May could be warmer and drier than normal.

The table below shows rainfall totals for the Michigan State University Enviroweather stations in southeast Michigan, as well as degree-days calculated using the Baskerville-Emin Method. Degree-day average for Commerce and Hudson is over five years, while Deerfield is over two years. Soil temperature range in Fahrenheit at 2-inch soil depth over the last week, and rainfall is in inches. For a refresher on degree-days and how to get this information in your area, see “Accessing growing degree days with Enviro-weather” from MSU Extension.

Rainfall and degree day totals as of April 24, 2019


Degree days (base 42)

Degree days (base 50)

5-Year degree day average (base 50)

Soil temperature range

Rainfall since April 1



















General information

If you are tired of working in the barn on a rainy day, register your fields on Driftwatch. This can help protect susceptible vegetable crops from dicamba drift. Driftwatch is a place dicamba applicators can go to satisfy the requirement to assess risks to neighboring crops. Another potential benefit this year is the Michigan Water Environment Association recommendation that biosolid applicators check Driftwatch for neighboring vegetable crops before applying. Some food safety auditors have expressed concerns about neighboring fields having biosolid applications; this is one way to notify applicators that you are growing produce that is consumed raw.

This is the first year the Michigan Department of Agriculture and Rural Development will be conducting routine inspections for the Food Safety Modernization Act (FSMA) Produce Safety Rule (PSR) for farms whose gross produce sales are over $500,000. Inspections will be announced and scheduled during harvest. If you want to prepare for inspection, you can sign up for an On Farm Readiness Review to take place on the farm later this summer. This free, confidential, voluntary program will help you assess where you stand in terms of PSR compliance.

Crop reports

We’ve had good weather for getting cabbage and other early season cole crops planted. The Enviroweather station at Deerfield is predicting that we are 84 degree days (so at least a week) away from overwintering cabbage maggot flies emerging. Cole crops that are going in should be getting an at-plant treatment, but we are still a few weeks out from peak cabbage maggot pressure. If managing organically, watch the Enviroweather cabbage maggot model and put out row covers when emergence begins, or avoid planting when flies are out.

Pepper transplants are in the greenhouse. Bacterial spot can start in the greenhouse, and plants cannot be cured once infection has taken place. Alternate copper and streptomycin at a five- to seven-day interval from the time the first true leaves appear to transplant. The copper rate will vary with its formulation (check the label of your specific copper product); the rate for Agri-Mycin 17 is 200ppm (0.5 pound for 50 gallons per acre).

Potato planting began at the start of the month, plants have not yet emerged. MSU has released a series of videos with tips on managing black leg, aerial stem rot and other bacterial soft rot disease across the field season. Early season management for these diseases include starting with certified disease, sanitizing cutting and planting equipment between seed lots, and limiting bruising during handling. See the videos linked below for more information

Some sweet corn has gone in but has not emerged. Note that sh2 varieties like soil temperatures consistently above 60 degrees Fahrenheit, so hold off on planting those varieties. The winter was harsh enough that Stewart’s wilt should not be an issue.

Seed corn maggot (who can also feed on cucurbit, pea and bean seeds) is currently flying, with the Deerfield Enviroweather station predicting peak fly egglaying for April 25. Many insecticide seed treatments have action against this pest.

I put out a black cutworm trap in Lenawee County last week and have caught four moths, which isn’t a significant number.

Tomato transplants are sizing up in the greenhouse. Remember that control of bacterial diseases, including bacterial spot and bacterial canker, starts in the greenhouse. In the greenhouse, rotate copper and streptomycin starting at the first true leaves and continue every five to seven days until the plants leave the greenhouse. The copper rate will vary with its formulation, check the label for your specific copper product. The rate for Agri-Mycin 17 in 200ppm (i.e., 0.5 pound for 50 gallons per acre). Keep an eye out for transplants with dark spots and yellow halos, and be ruthless when rouging out diseased transplants and their neighbors. Plants do not recover from bacterial diseases in the field. For more information, see “Protect greenhouse tomato transplants from bacterial spot” from MSU Extension.

If your tomato transplants are getting tall, limiting water, lowering overnight temperatures and brushing can help prevent them from getting too tall and leggy before planting.


Save the date! The 2019 Great Lakes Fruit, Vegetable, and Farm Market EXPO is scheduled for Dec. 10-12 in Grand Rapids, Michigan.

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