East Michigan vegetable update – June 21, 2017

Cooler day temperatures and recent rain should help prevent soil crusting from forming too rapidly.


Ask and ye shall receive. Rain came aplenty across the region over the span of a few days. Michigan State University Enviroweather stations picked up at most 3.77 inches in Linwood and at least 0.06 inch in Freeland. This reflects grower reports as well, with at most 5 inches and at least 0.30 inch across the region.

For some, that rain was welcomed, while others are now in a waiting game to plant their last pumpkin and sweet corn patches. The cooler day temperatures and repeated small rain events should help prevent soil crusting from forming too rapidly.

The table below shows growing degree-days (GDD) base 50 F since March 1, rainfall (inches since April 1) accumulations and soil temperature ranges (Fahrenheit over the last week) to date from MSU Enviro-weather stations in the region.

Rainfall and GDD totals as of June 21, 2017


GDD (+ added from last week)

GDD 5-year average

Rainfall (+ added from last week)

Rainfall 5-year average


735 (+ 139)


8.15 (+ 1.26)



772 (+ 128)


7.67 (+ 2.29)



864 (+ 140)


10.72 (+ 1.65)



812 (+ 133)


10.21 (+ 2.15)



790 (+ 135)


6.98 (+ 0.06)



796 (+ 123)


6.85 (+ 1.65)



709 (+ 129)


13.76 (+ 3.77)



793 (+ 135)


8.96 (+ 1.51)



799 (+ 144)


7.57 (+ 0.91)



695 (+ 128)


8.34 (+ 1.73)



Organic cole crops are starting to show swede midge damage from the first generation of feeding. Two weeks ago I could not find any larvae in leaves, but yesterday, June 20, I found a gradient of collards damaged leaves with older yellow larvae, and undamaged leaves with young white larvae.

Swede midge adults were also seen on plants. They were apparently stuck along two collard rows on the eastern edge of a large cole crop planting. One row switched to broccoli about one-third of the way down and the midges had begun infesting those too. The rows west of the collards were unaffected.

Mustard greens, collards and kale harvest has begun. Head lettuce harvest in Imlay City, Michigan, has begun. Leaf lettuce and spinach have been bolting.

Sweet corn plantings have been delayed by rain. Earliest plantings are sending out tassels. I will be placing two earworm traps in our region within the next week when silking begins.

Watermelons and cantaloupes are setting fruit in earliest plantings that used tunnels or hotcaps. They are growing out of their wind-damaged tattered leaves now in the Bay. The plants I saw in Armada, Michigan, last week looked fantastic. One more planting was still slated to go in this week.

Pickling cucumber plantings were at 35 percent completion last week. Seeds are sprouting quickly with the heat and moisture in the subsoil. Direct market pickles are already being picked on one farm, with harvest volume predicted to increase over the weekend.

I’ve noticed fresh market growers planting cucumbers earlier to avoid downy mildew pressure later in summer. MSU Extension plant pathologist Mary Hausbeck has put out her downy mildew recommendations for 2017 for processing pickles, which are grown into late summer through heavy downy mildew pressure when Bravo alone is usually not enough protection.

Zucchini and yellow summer squash plants are of varying sizes across the region, but most are beginning to bloom. The earliest growers are going to start first pickings this coming weekend.

Winter squash and pumpkin plantings are finished in many places, and delayed by rain in others.

Some tablestock potatoes are flowering and tubers are ranging from marble-size to 2 inches in diameter. There were some reports of aerial stem rot, blackleg and tuber soft rot reported last week. A nice bulletin about that disease complex is “Michigan Potato Diseases: Tuber Soft Rot, Blackleg and Aerial Stem Rot” from MSU.

Tomatoes are in various stages of growth and harvest. The heated hoophouse types are still being picked. Field plantings are between “I got ‘em in yesterday” and “I could start picking green tomatoes today.” No serious disease pressures have been reported, but Roundup injuries have.

Peppers are flowering and setting fruit. Plants are small, almost without exception. The weather has not been favorable for most of our pepper plantings.

Red beets are being harvested.

Early strawberry varieties are small and misshapen this year due to a variety of comingling environmental conditions, but primarily from extreme wind and lack of good pollination conditions when those varieties were in bloom. The later varieties have gotten mushy from the recent rains. Renovation can begin any time now once you decide to stop picking.

Garlic scapes were being harvested last week, and the rain over the weekend caused a second flush on smaller plants that had not produced yet. Cloves are beginning to singulate from single bulbs.

Upcoming meetings

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.”

The Midwest Mechanical Weed Control Field Day is scheduled for Sept. 26 at the MSU Horticulture Farm. For more information and registration, see “Midwest Mechanical Weed Control Field Day.”

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.

Please contact me at phill406@msu.edu or 616-901-7513 to pick up any suspected disease samples from your farm, or send the diseased plant parts to MSU Diagnostic Services.

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