East Michigan vegetable update – June 3, 2020

Should be a busy week of planting with good moisture and growing conditions.

Zucchini and green beans in high tunnel
Zucchini and green beans in this Gagetown, Michigan, high tunnel are being used as a rotation crop with tomatoes. Photo by Dan Warack.


The Bay and Thumb region received 0 to 1 inches of rain last night, and pretty much caught up to five-year temperature averages in the last week. There is another chance of rain on Friday, June 5, with more typical spring temperatures. Next week could be wetter than normal on the latter half.

You can find more detailed weather information for your area by visiting the Michigan State University Enviroweather station closest to you:

Seed and root maggots in cole crops and onions are in their peak egglaying stages, and European corn borer moths should be emerging this week from overwintered pupae. It could be a good time to target a spray on any recently planted cole crops that are in the ground and young seeded onions. Here is a table that summarizes the insects of concern and the degree days that signify when they will be laying eggs in the areas around seedlings. I used Lapeer as an example. The onion maggot model is from NEWA.


Seed corn maggot emergence - base 39 F

Onion maggot emergence – base 40 F

Cabbage maggot emergence - base 43 F

European corn borer emergence – base 50 F

Current degree days (Lapeer)





Overwintering generation start to emerge and lay eggs

201 (occurred April 10)

390 (occurred May 18)

298 (occurred May 13)

450 (predicted to occur June 5)

Peak flight and egg laying of overwintering generation

342 (Occurred on May 1)

735 (Occurred June 1. A spray could be targeted over the next two weeks on young onion crops.)

565 (Occurred on May 27. A spray could be targeted over the next two weeks as transplanted cole crops and seeded root crops go in.)


Peak flight and egg laying of first generation





Pest updates

Striped cucumber beetles out on squash seedlings.

Flea beetles are out on Brassicas and potatoes.

Leafhoppers are out in high numbers in west and central Michigan. I have not heard reports from our region.

Aphids and thrips can thrive in these warm days and are worth scouting for before their populations grow too large.

Colorado potato beetles out on potatoes. One grower reported they know when they’re out because they show up in the swimming pool filter.

Disease issues coming into MSU Plant & Pest Diagnostics include some pith necrosis issues in field planted low-tunnel tomatoes and Pythium root rots in hydroponic leafy greens.

Crop progress

Strawberries are about 1 feet tall and flowers are dropping to develop fruit. One grower estimates harvest by June 17.

Zucchini, summer squash, beans and tomatoes are coming out of hoop houses now.

Asparagus picking continues. When picking finishes up and ferns are allowed to grow, MSU plant pathologist Mary Hausbeck recommends starting early this year with preventive management of purple spot.

Potatoes are being hilled and herbicide applications are occurring. A funny thing about potatoes is that you cover them up every so often with hilling, and this recreates a “preemergence” condition for the crop. In this condition, Dual Magnum, League and Matrix can be sprayed for weed control. Matrix and Dual Magnum have some efficacy on both broadleaves and grasses while League only works on broadleaves. Of those herbicides, League and Matrix are the only ones you can spray on emerged weeds less than 1 inch tall. When hilling is finished for the season, League can also be sprayed directly over the emerged potatoes. For grass control in this situation, use Poast or Select Max.

Onions should be scouted for thrips and foliar diseases. Stemphylium is one of the main diseases of concern now in Michigan onions and is favored by these warm, humid nights. The best fungicides for this disease are Miravis Prime plus Bravo, Luna Tranquility plus Bravo, and Tilt plus Manzate. Hausbeck recommends starting a preventative program with these most effect fungicides because a less effective fungicide can allow disease pressure to build high enough that even the best products cannot bring the infection down to acceptable levels in the late season. In this scenario, you are out the money and out the yield.

Pickling cucumbers have been going in. Acres are down because of end-users not consuming as much food-service packaged pickles during the pandemic (fast-food, sporting events, etc.). On a grower visit, we tried to estimate how much relish is moved at baseball games. We didn’t have much data to work with then, but I did a little digging.

In 2018, the National Hot Dog and Sausage Council predicted that baseball fans would consume 24 million hot dogs and sausages across the 162 regular season games. If a quarter of those hot dogs were garnished with a tablespoon of relish, that would be 6 million tablespoons, or 370,000 cups. If we assume the density of relish is 8.5 ounces per cup, then that is 3,145,000 ounces, or 196,665 pounds of relish. Relish is made from the ugly shaped and broken pickles that do not make good whole, spears, stackers or chips, and might be somewhere around 10% of the total yield: about 670 pounds per acre of relish pickles out of 6,700 pounds per acre total yield.

According to that napkin math, an MLB season’s worth of relish would take 29 acres of pickles to fulfill, as the byproduct of the more lucrative whole, spear, stacker and chip market. Multiply that by every other sport played at that level across America (basketball, football, hockey) and then every lower league for each sport, and then non-sporting events that put relish out for hot dog stands and you can see how acres get slashed.  That’s just relish, and does not factor in hamburgers with pickle chips, other sandwiches served with a pickle spear, and those individually bagged whole circus pickles.

Sweet potatoes are being planted this week. Have you ever wanted to grow sweet potatoes? If so, contact Lori Setera from Forgotten Harvest at 248-302-7472 or lsetera@forgottenharvest.org. They have 30,000 extra slips of Covington due to an error from the supplier. That is about 2 acres worth of sweet potatoes with 40-inch between row spacings, and 10 inches between plants in the row.

Great Lakes Vegetable Producer’s Network

MSU Extension is participating in a live, weekly roundtable discussion during the growing season for commercial vegetable producers in the Great Lakes and Midwest region. Join us! We broadcast live via Zoom at 12:30 p.m. ET/11:30 a.m. CT every Wednesday from the first week of May to the first week of September. Listen live or later. If you have a pressing vegetable production issue that you would like discussed, simply email it, along with your phone number, to greatlakesvegwg@gmail.com

On-tap for next week, June 10: Do’s and Don’ts for Sending Samples and Reading Results


An old friend of mine completed suicide on May 24. She was engaged to be married in July and was one of the most positive people I had ever met. I don’t think anyone saw it coming. Completing suicide takes thought and planning. Once plans have been made, some people appear more at ease and it may be confusing. Asking outright if someone is thinking about it or planning it is a legitimate question and can save their life. They are not planning a secret birthday party. They know it is destructive to themselves and others and it is an act of love to ask. You will not be let in unless you ask.

This season is full of uncertainty to a degree that can bring a heavy mental load on you as a farmer. MSU is partnering with Pine Rest to offer teletherapy to connect growers to mental health professionals. Keep this in your back pocket for yourself and other members of your community.

There are two ways farmers can access services. You can reach out to Eric Karbowski, MSU Extension farm stress educator, at 989-317-4079 or karbows8@msu.edu, or self-refer for services by calling 866-852-4001. Please note that self-referrals must state “MSU Extension Teletherapy” to qualify for the pilot project.  

Please contact me at phill406@msu.edu or 616-901-7513 with questions, concerns, or to schedule a farm visit. You can also send plant materials to MSU Plant & Pest Diagnostics.

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