Southeast Michigan vegetable update – May 1, 2019

Rain halts field work and cool temperatures slow plant growth.


The weather in the last week took a wet and cold turn. This has led to soil temperatures falling into the mid-40s at a 4-inch depth. Last night brought up to 2 inches of rain in some parts of our region. Another low pressure system from the south is moving in, so more rain is in the forecast. The weekend looks to be dry, but beyond that there is a chance of more rain.

Long-term forecast predictions have shifted for the month of May, with predictions calling for cooler and wetter than normal weather (especially in the next one to two weeks).

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, with number in parenthesis indicating rainfall since the last report. 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 May 1


Degree days (base 42)

Degree days (base 50)

5-Year degree day average (base 50)

Soil temperature range

Rainfall since April 1






4.44 (+2.43)






4.6 (+2.32)






5 (+3.09)

General information

There are training videos available for training workers in accordance with the 2016 Worker Protection Standards. The videos can be found on the EPA PERC website and are available in English and Spanish. This training needs to take place annually and a record of the training needs to be taken. There needs to be a certified applicator in the room to monitor the training and answer questions, even while the video is shown.

Crop reports

Light asparagus harvest has begun.

Cole crop planting continued until the rain began. The Enviroweather station at Deerfield is predicting adult cabbage maggot emergence beginning in 42 degree days, so emergence will likely begin later this week.

Peas have been planted and emerged.

Pepper and tomato transplants should continue to be watched for diseases, especially as planting is delayed. Now that we have cloudy days and damp air, all vegetable transplants should be managed to prevent botrytis. This disease is primarily prevented by manipulating the greenhouse environment to keep relative humidity below 85% and minimizing periods of leaf wetness. Vent as you are able and promote air movement. Heat as necessary to manage relative humidity.

For other vegetables and herbs in the greenhouse, there are some nice summary tables available with what is currently registered for diseases and insects.

Some sweet corn plantings have emerged and are a couple of inches tall.

I’ve caught eight black cutworm moths in the last week in Monroe County. The numbers up to this date suggest there will be sporadic cutworm damage. The low pressure systems that moved through last night and are predicted to move through tomorrow have the potential, according to Insect Forecast, to bring in cutworm and armyworm moths.

Rhubarb is up, growth is slow with the cool weather.


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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