Flint, Michigan area urban agriculture report for August 13, 2015

Current updates about urban and semi-rural small scale diversified vegetable farm fields, hoop houses and market gardens in the Flint, Michigan, area.

Downy mildew on cucumber.
Downy mildew on cucumber.


According to the Michigan State University Enviro-weather station in Flint Michigan, temperatures for the past week ranged from a low of 53.8 degrees Fahrenheit to a high of 83 F, a cooler week than the previous week. We are at 1,911 growing degree days (GDD) base 50; in August 2014 we were a bit lower in terms of degree-day totals. The rainfall total for the year to date in Flint, Michigan, is 15.6 inches; we had 0.53 inches recorded at the Flint Enviro-weather station in the past week, primarily falling this past Monday, Aug. 10.

Disease concerns in our vegetable crops are elevated, with Genesee County now experiencing confirmed cases of downy mildew in cucumbers. Late blight in potatoes has been recently found in several counties in central and western Lower Michigan, including Montcalm and St. Joseph counties.

Crop reports

According to research done in the hoop houses located at MSU’s Student Organic Farm and Michigan State University Extension educator observations from the field, fall crops are being planted and warm season crops are being harvested out of area hoop houses due to the season extension technology used by many of our area growers. In Flint, Michigan, area hoop houses and market gardens, growers are identifying pests and diseases, harvesting numerous crops, removing spent crops, preparing beds, seeding carrots and other cool season vegetables and starting transplants (spinach, lettuce and other greens) for fall plantings. Outdoors, growers are planting daikon radishes and leafy Asian greens in market gardens.

Powdery mildew on cucumber and other squash family crops continues. White mold has shown up on isolated hoop house tomato plants. This disease produces black sclerotia, overwintering structures, inside the brittle stems.

White mold on tomato White mold showing sclerotia

White mold symptoms on a tomato plant.

Insect problems including damage from squash bugs, Japanese beetles and flea beetles are readily seen in some fields. Some hail damage from the storms of the previous week was detected on vegetable plants and produce as well.

Flea beetle damage

Flea beetle damage to kale plant.

Growers need to be especially vigilant for downy mildew in cucumbers, as it has now been detected and confirmed in Genesee County in the past week. It is time to take action if you are still actively cropping cucumbers. You can use fungicides (copper-based materials for organic systems) to slow down disease progression and protect plants not yet infected. Michigan State University Extension vegetable pathologist Mary Hausbeck is recommending shorter spray intervals to stay on top of downy mildew, especially when it’s confirmed in your area. If your cucumber plants are winding down (majority of the crop is already harvested), the recommendation is to promptly pull them out and destroy them so they don’t harbor the disease on your farm.

Potato late blight is the other serious disease that has been found in several Michigan counties.

The Hausbeck Lab website is a helpful resource for urban producers with the current disease concerns in our state, with links to current monitoring maps and disease management recommendations.

Going to area farmers markets now

According to a Michigan State University Extension food systems educator, area growers are harvesting a large crop of tomatoes, cucumbers, bell peppers, summer squash, green beans, zucchini and many herbs from area hoop houses and farm fields this week.

For more information on what is available at fresh markets now, the Michigan fruit and vegetable availability chart, including season extension availability, can be accessed on the Michigan Fresh website.

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