Southeast Michigan vegetable update – June 7, 2017

Dry weather allows for planting and weed control measures, but cool temperatures are slowing plant growth.

These industrious striped cucumber beetles are busy creating damage and the next generation of cucumber beetle. Photos by Marissa Schuh, MSU Extension.
These industrious striped cucumber beetles are busy creating damage and the next generation of cucumber beetle. Photos by Marissa Schuh, MSU Extension.


The cool evening temperatures are slowing plant growth and high winds have some plants looking ragged. The lowest points in fields with heavy soil are still very wet, but the sandier soils are quite dry. Weather will shift as we move toward the weekend and we are looking at significantly warmer temperatures next week.

Now that fields are drier, weed control measures are occurring in many crops. Note that many pre-emergent herbicides need water to move them into the soil and there isn’t a significant chance of rain in the forecast.

How long you can wait after application for water to be applied varies. Generally, the longer you wait, the less effective the product will be, so try to get water on the field in under 24 hours if possible. Heavy residue may also impact the ability of the herbicide to penetrate the soil and prevent weed seeds from germinating.

The table below presents rainfall (in inches) for the Michigan State University Enviroweather stations in southeast Michigan with the amount of change from last week reported. Degree days (starting March 1) calculated using the Baskerville-Emin Method.

Rainfall and degree-day totals as of June 7

Enviroweather Station

Degree-days (base 50)

5-year degree day average (base 50)

Rainfall since April 1 (inches)


473 (+89)


6.58 (+0.07)


619 (+111)

Not available

7.68 (+0.04)


521 (+107)


7.17 (+0.02)


Asparagus harvest has concluded.

Hoophouse cucumbers have just begun being harvested on some farms. Quality is good and no disease issues have been reported.

Cole crops are handling cooler weather well. Cabbage planting continues and some transplanted broccoli is heading. Sprays for caterpillar pests are ongoing.

Garlic is waist height and scapes are being harvested.

Watermelon and muskmelon transplanting continues, with a fair amount already planted on plastic and bare ground.

Pea harvest is likely to begin next week.

Pepper planting continues. Plants aren’t growing quickly due to the cooler weather. Bacterial issues have been reported in jalapeno transplants in other parts of the state. This issue is often seed-borne, so keep an eye on jalapeno transplants.

Potato planting has finished up or is about to. There are reports of potatoes coming into the campus lab with fusarium dry rot that is resistant to Maxim, so reconsidering at next year’s seed treatment may be warranted if this issue is popping up.

Looking at the Potato Volunteer Survival map, which predicts the risk of volunteer potato survival based on winter soil temperatures, models suggest southeast Michigan and much of the state could potentially have high numbers of volunteer potatoes appearing this year. This is problematic as these volunteers can serve a source of inoculum for late blight. For more information on volunteer potatoes and the model, see “Potential survival of potato volunteers in Michigan” by MSU Extension.

Pumpkin planting continues, with some poor stand emergence reported. Squash vine borer will likely begin flying in just over a week.

Winter squash planting is underway. Summer squash planted on plastic and housed under low tunnels is now large enough that tunnels have been removed—flowers are out and fruit is forming.

Striped cucumber beetles are feeding in fields (see photo above). For a refresher on this pest, see MSU Extension’s “Striped and spotted cucumber beetles as pests of cucurbits in Michigan.”

Strawberry harvest has begun, with disappointing strawberry yield and quality reported. This is likely due to warm, winter temperature and a cold, cloudy spring that prevented vigorous leaf growth. For more details on strawberries, see “East Michigan fruit update – June 6, 2017” by MSU Extension fruit educator Bob Tritten.

Sweet corn in the earliest plantings are beginning to tiller. I’ve seen some severe cases of Stewart’s wilt, which is more likely to be seen this year due to a warm winter that allowed high numbers of flea beetles to overwinter. Infected sweet corn will develop long yellow, white or necrotic stripes. Severe infections likely occurred when the plants were seedlings, and plants are less susceptible to Stewart’s wilt as they grow (especially once past seven leaf stage).

Little can be done after infection and expect stunting and lower yield from impacts areas. For more information on flea beetles and Stewart’s wilt, see the MSU Extension article, “Stewart’s wilt in sweet corn 2017.”

stewarts wilt

Stewart’s wilt produces streaks on the leaf, which start yellow and eventually become necrotic. These streaks extend throughout the whole leaf, indicating this particular sweet corn variety doesn’t have strong resistance to Stewart’s wilt.

Sweet potato is being planted.

Processing tomato planting continues.

Market tomato field work continues as stakes are being placed. There is small fruit on some plants. Colorado potato beetles have done a lot of feeding on some farms.

Contact me at any time for pest and disease sampling at 517-264-5309 or I make updates regularly on Twitter at @SoutheastMIVeg.


If you’re interested in participating in a statewide survey of squash bees, there will be a webinar June 15 from 3-4:30 p.m. focused on squash bee identification and how to report sightings to MSU researchers. For information and registration, visit “Squash Bee Pollinators and EMG Citizen Science Project.”

Those interested in the burgeoning local oat market can attend the “Oat Twilight Crop Walk” from 6-8:30 p.m. at Zilke Vegetable Farm in Milan, Michigan. For more information and registration, see “Local oats for fresh milling featured at Washtenaw County Field Day.”

The 2017 MSU Weed Tour will be June 28 at the MSU Agronomy Farm. For more information and registration, see “2017 MSU Weed Tour scheduled for June 28.”

Hotels are filling up for the Great Lakes Fruit and Vegetable EXPO, Dec. 5-7, in Grand Rapids, Michigan. The combination of grower-focused, research-backed presentations and an amazing exhibit hall make it a can’t-miss event. 

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