Southeast Michigan fruit update – August 11, 2026
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EmailRed Haven harvest continues and brown marmorated stink bugs are emerging.
Welcome to the 20th in-season fruit article update for Southeast Michigan for the 2026 season. Throughout the season these updates will include information about the weather in the past week and the upcoming week, a fruit-by-fruit guide to current conditions with appropriate pest and disease updates, and other relevant observations.
General observations
The last week didn’t differ much from the weeks before with continued heat and humidity. While we experienced some rainy days the accumulation was the same as the week before. We are expecting storms this week on Tuesday and Wednesday, Aug. 11 and 12, as well as showers over the weekend. High temperatures will stay in the 80s for the next week while overnight lows will stay in the 60s dropping to the 50s over the weekend.
Growers are continuing to pick blueberries, fall raspberries and Red Haven peaches along with early apples like Paula Red. European style plums and more grape varieties are starting to take on color.
Powdery mildew is again the biggest disease risk this week, though there is also risk for cherry leaf spot and grape downy mildew. Brown marmorated stink bugs are starting to emerge in apple orchards and spotted wing drosophila continues to be a concern in berry crops.
The MDHHS has updated their guidance on Cyclospora back to routine recommendations for salad greens, which seem to have been the origin of the recent outbreak.
Michigan State University Extension educators recently published the 2026 apple maturity prediction dates, including the apple harvest prediction dates for southeast Michigan.
Our weekly video IPM updates have concluded for the season. See the recordings of the weekly fruit meetings for Southern Michigan on MSU’s Kaltura Media Space, including the final June 23 meeting.
Fruit-by-fruit conditions
Apples: Apples in the region are starting to take on color. We are in the main pattern of summer cover sprays. Early cultivars like Paula Red have been harvested. Our main concerns at this time of year are powdery mildew, apple maggot, brown marmorated stink bug and codling moth.
Blueberries: The main harvest season continues. Spotted wing drosophila and fruit rot management are priorities.
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Brambles: The first fall raspberries are being picked along with some blackberries. Poor pollination and crumbly berries have been seen at some sites in fall raspberries, which may be due to unsuitable weather conditions during bloom. Fruit rots and spotted wing drosophila management are the main concerns for production.
Cherries: Harvest has wrapped up in both sweet and tart cherries at farms that decided to harvest this year. Unharvested fruit can be a reservoir for spotted wing drosophila (SWD), so if you have other crops that are susceptible to SWD, like blueberries and brambles, you may want to remove them.
Grapes: Veraison has started in early hybrid wine grapes like Marquette and some table grapes like Fredonia while other cultivars like Concord remain green.
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Peaches and nectarines: Red Haven harvest has started. For late cultivars there is still time to do some brown rot control, but check your pre-harvest intervals.
New bulletin: “Best Practices for Peach Orchards with Reduced Crop Load”
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Pears: Pears are sizing up in the region. Local scouts have continued to report sightings of pear psylla adults in orchards.
Plums: European style plums are starting to color, and almost all Japanese style plums have been harvested.
Strawberries: Harvest is done in the region and most growers have already renovated.
Insect conditions
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More in-depth information can be found by watching the latest weekly fruit meetings on MSU’s Kaltura Media Space (these may take a few days to upload after the meetings).
New MSU article: “Don't trust the calendar: Why trapping matters during unusual weather”
New MSU fact sheet: Managing Ambrosia Beetles in Apples
Aphids: Woolly apple aphid populations in apple are moving towards terminals and populations are building.
Apple maggot: Continued catches of low numbers have been reported in the region (two to three per ball) for the last four weeks. Counts at Fennville remain low.
Blueberry maggot: No catch reported in Fennville.
Borers: Catch of greater peachtree borer is down and stable counts of lesser peachtree borer have been reported in Fennville.
Brown marmorated stink bug: Adults usually emerge in August. Nymphs have been reported in Southeast Michigan and adults have been reported in Northern Ohio. Because adults are active so close to harvest you need to pay close attention to your pre-harvest intervals.
Codling moth: Adult catches are climbing regionally and stable in Fennville, including some sites over threshold.
Grape berry moth: Counts in Fennville have remained stable.
Japanese beetle: Counts have been declining regionally but have climbed in Fennville, though they are still causing problems. Kaolin clay can be a deterrent and perimeter sprays can also be effective for keeping them under control.
Mites: Mite counts have been dropping regionally. European red mites and rust mites are responsible for some bronzing in orchards. Two spotted spider mites will be evidenced by webbing.
Oriental fruit moth: Counts have declined at sites in Southeast Michigan and Fennville.
Pear psylla: There has been increased adult and nymph activity in orchards along with some evidence of damage.
San Jose scale: There are seeing waxed up scales in the region, meaning the control window has shut.
Spotted lanternfly: Look for nymphs in parts of the state that have documented populations (Detroit, Monroe County, Oakland County).
Spotted wing drosophila: Consistent counts in traps in Southeast Michigan and down in Fennville. This pest often prefers fruit to the traps, so low trap counts do not necessarily mean low risk in fruit.
Disease conditions
Apple scab: We don’t anticipate risk for secondary scab infections this week.
Cherry leaf spot: We anticipate slight risk from Aug. 12-13. See this 2024 article on cherry leaf spot management.
European brown rot: Stone fruits are susceptible to infection around 3 weeks after shuck split and again 3 weeks before harvest through the harvest period. We do not expect risk this week.
Fire blight: Since we have moved out of bloom there is low risk in apples and pears, however if there is hail damage growers should spray for fire blight.
Grape black rot: Control for grape black is most important immediately pre-bloom and during bloom. See this 2014 article for grape black rot management options and consult E-154. We do not anticipate risk this week.
Grape downy mildew: We anticipate moderate to high risk from Aug. 12-14.
Grape powdery mildew: We are expecting high risk from Aug. 16-18.
Phomopsis: In blueberries, the Phomopsis fungus is active from bud swell until after harvest.
Powdery mildew of apple and pear: There will be airborne conidia all week but models indicate that conditions won’t be right for infection.
Seasonal weather update
In the last week, Southeast Michigan has seen an average of 6.6 hours of rain accumulating to 0.5 inches of precipitation.
| Liquid Precipitation Accumulation Mar. 1- August 11, 2026, issued August 11, 2026 | ||||
|---|---|---|---|---|
| Station (County) | Rainfall Total (in.) Current | Hours with Rainfall Current | Rainfall Total Average (5 Yr.) | Hours with Rainfall Average (5 Yr.) |
| Commerce (Oakland) | 16.9 | 234 | 17.3 | 261 |
| Deerfield (Monroe) | 21.6 | 238 | 15.4 | 247 |
| East Lansing MSU Hort (Ingham) | 18.4 | 259 | 15.6 | 251 |
| Emmett (St. Clair) | 17.6 | 266 | 15.2 | 256 |
| Flint (Genesee) | 16.6 | 244 | 16.2 | 264 |
| Freeland (Saginaw) | 17.7 | 219 | . | . |
| Hudson (Lenawee) | 18.3 | 248 | 15.7 | 252 |
| Ithaca (Gratiot) | 19.0 | 248 | 13.9 | 240 |
| Lapeer (Lapeer) | 16.5 | 255 | 16.1 | 274 |
| Linwood (Bay) | 19.5 | 253 | 14.1 | 240 |
| Pigeon (Huron) | 16.4 | 258 | 13.7 | 256 |
| Richville/Frankenmuth (Tuscola) | 18.8 | 235 | 15.5 | 235 |
| Romeo (Macomb) | 19.0 | 237 | 18.1 | 250 |
| Sandusky (Sanilac) | 16.2 | 238 | 14.0 | 268 |
| Average of stations in this region: | 18.0 | 245.1 | 15.4 | 253.4 |
| Difference in Liquid Precipitation Accumulation from Mar. 1 observed August 4 and August 11, 2026; issued August 11, 2026 | ||||||
|---|---|---|---|---|---|---|
| Rainfall Total (in.) | Rainfall Total (in.) | Hours with Rainfall | Hours with Rainfall | |||
| Station (County) | 4-Aug | 11-Aug | Difference | 4-Aug | 11-Aug | Difference |
| Commerce (Oakland) | 16.5 | 16.9 | 0.4 | 229 | 234.0 | 5.0 |
| Deerfield (Monroe) | 20.1 | 21.6 | 1.5 | 226 | 238.0 | 12.0 |
| East Lansing MSU Hort (Ingham) | 17.2 | 18.4 | 1.2 | 247 | 259.0 | 12.0 |
| Emmett (St. Clair) | 17.3 | 17.6 | 0.4 | 260 | 266.0 | 6.0 |
| Flint (Genesee) | 16.1 | 16.6 | 0.5 | 237 | 244.0 | 7.0 |
| Freeland (Saginaw) | 17.6 | 17.7 | 0.1 | 217 | 219.0 | 2.0 |
| Hudson (Lenawee) | 17.5 | 18.3 | 0.8 | 240 | 248.0 | 8.0 |
| Ithaca (Gratiot) | 18.9 | 19.0 | 0.1 | 244 | 248.0 | 4.0 |
| Lapeer (Lapeer) | 16.1 | 16.5 | 0.4 | 248 | 255.0 | 7.0 |
| Linwood (Bay) | 19.5 | 19.5 | 0.1 | 250 | 253.0 | 3.0 |
| Pigeon (Huron) | 16.4 | 16.4 | 0.0 | 256 | 258.0 | 2.0 |
| Richville/Frankenmuth (Tuscola) | 18.6 | 18.8 | 0.2 | 229 | 235.0 | 6.0 |
| Romeo (Macomb) | 18.2 | 19.0 | 0.8 | 230 | 237.0 | 7.0 |
| Sandusky (Sanilac) | 15.9 | 16.2 | 0.4 | 227 | 238.0 | 11.0 |
| Average of stations in this region: | 17.6 | 18.0 | 0.5 | 238.6 | 245.1 | 6.6 |
In the short term, we are expecting scattered storms and showers on Tuesday and Wednesday and more showers over the weekend with fair weather in between. Highs for the next week will be in the low-80s while overnight lows will be in the mid-60s for most of the week before dropping over the weekend. In the next month we are expecting the rest of August to exhibit above normal temperatures and above normal precipitation.
Our regional average growing degree day accumulation for the season are about seven days ahead of the long term normals and about three days ahead of the five-year average. In the last week, we accumulated on average 213 GDD at 42 F, 192 GDD at 45 F, and 157 GDD at 50 F (see table below). Read this Michigan State University Extension article to learn more about degree days: Understanding growing degree-days.
| Degree Day Accumulation Mar. 1-August 11, 2026 Forecast from Aug. 12-18, 2026; issued August 11, 2026 | |||||||||
|---|---|---|---|---|---|---|---|---|---|
| Station (County) | Degree Days Base 42°F Current | Degree Days Base 42°F Average (5 Yr.) | Degree Days Base 42°F Forecast | Degree Days Base 45°F Current | Degree Days Base 45°F Average (5 Yr.) | Degree Days Base 45°F Forecast | Degree Days Base 50°F Current | Degree Days Base 50°F Average (5 Yr.) | Degree Days Base 50°F Forecast |
| Commerce (Oakland) | 2940 | 2818 | 3147 | 2558 | 2446 | 2745 | 1969 | 1876 | 2120 |
| Deerfield (Monroe) | 3222 | 3073 | 3423 | 2817 | 2684 | 2997 | 2186 | 2086 | 2331 |
| East Lansing MSU Hort (Ingham) | 3007 | 2880 | 3203 | 2618 | 2503 | 2793 | 2015 | 1925 | 2155 |
| Emmett (St. Clair) | 2727 | 2663 | 2923 | 2360 | 2296 | 2535 | 1799 | 1736 | 1939 |
| Flint (Genesee) | 3090 | 2978 | 3297 | 2706 | 2599 | 2892 | 2110 | 2016 | 2261 |
| Freeland (Saginaw) | 2823 | 2826 | 3015 | 2453 | 2456 | 2624 | 1879 | 1890 | 2015 |
| Hudson (Lenawee) | 3092 | 2999 | 3296 | 2701 | 2628 | 2884 | 2096 | 2051 | 2244 |
| Ithaca (Gratiot) | 3019 | 2954 | 3214 | 2639 | 2578 | 2813 | 2049 | 1998 | 2188 |
| Lapeer (Lapeer) | 2900 | 2791 | 3095 | 2527 | 2422 | 2702 | 1952 | 1857 | 2091 |
| Linwood (Bay) | 2586 | 2622 | 2771 | 2225 | 2264 | 2390 | 1677 | 1717 | 1806 |
| Pigeon (Huron) | 2657 | 2669 | 2844 | 2298 | 2309 | 2465 | 1745 | 1763 | 1876 |
| Richville/Frankenmuth (Tuscola) | 2912 | 2880 | 3104 | 2537 | 2506 | 2709 | 1958 | 1929 | 2095 |
| Romeo (Macomb) | 2977 | 2845 | 3178 | 2596 | 2471 | 2777 | 2008 | 1896 | 2154 |
| Sandusky (Sanilac) | 2783 | 2717 | 2970 | 2418 | 2355 | 2585 | 1855 | 1802 | 1987 |
| Average of stations in this region: | 2909 | 2837 | 3106 | 2532 | 2465 | 2708 | 1950 | 1896 | 2090 |
| Difference in Degree Day Accumulation from Mar. 1, 2026 observed August 4 and August 11, 2026; issued August 11, 2026 | |||||||||
|---|---|---|---|---|---|---|---|---|---|
| Station (County) | Degree Days Base 42°F | Degree Days Base 42°F | Degree Days Base 42°F | Degree Days Base 45°F | Degree Days Base 45°F | Degree Days Base 45°F | Degree Days Base 50°F | Degree Days Base 50°F | Degree Days Base 50°F |
| 4-Aug | 11-Aug | Difference | 4-Aug | 11-Aug | Difference | 4-Aug | 11-Aug | Difference | |
| Commerce (Oakland) | 2721 | 2940 | 218.8 | 2361 | 2558 | 197.0 | 1806 | 1969 | 162.7 |
| Deerfield (Monroe) | 3005 | 3222 | 216.6 | 2621 | 2817 | 195.7 | 2025 | 2186 | 160.7 |
| East Lansing MSU Hort (Ingham) | 2796 | 3007 | 211.0 | 2427 | 2618 | 190.7 | 1860 | 2015 | 154.9 |
| Emmett (St. Clair) | 2515 | 2727 | 211.8 | 2169 | 2360 | 191.2 | 1643 | 1799 | 156.1 |
| Flint (Genesee) | 2862 | 3090 | 227.8 | 2499 | 2706 | 206.8 | 1938 | 2110 | 172.0 |
| Freeland (Saginaw) | 2619 | 2823 | 204.1 | 2270 | 2453 | 183.1 | 1731 | 1879 | 147.9 |
| Hudson (Lenawee) | 2887 | 3092 | 205.0 | 2517 | 2701 | 183.7 | 1947 | 2096 | 148.6 |
| Ithaca (Gratiot) | 2805 | 3019 | 214.0 | 2446 | 2639 | 193.2 | 1891 | 2049 | 158.2 |
| Lapeer (Lapeer) | 2679 | 2900 | 220.5 | 2327 | 2527 | 199.9 | 1787 | 1952 | 164.8 |
| Linwood (Bay) | 2397 | 2586 | 188.5 | 2058 | 2225 | 167.0 | 1544 | 1677 | 132.5 |
| Pigeon (Huron) | 2454 | 2657 | 202.6 | 2116 | 2298 | 182.1 | 1598 | 1745 | 146.6 |
| Richville/Frankenmuth (Tuscola) | 2698 | 2912 | 213.5 | 2344 | 2537 | 193.2 | 1800 | 1958 | 158.2 |
| Romeo (Macomb) | 2750 | 2977 | 226.6 | 2390 | 2596 | 205.8 | 1838 | 2008 | 170.2 |
| Sandusky (Sanilac) | 2563 | 2783 | 219.7 | 2220 | 2418 | 197.8 | 1692 | 1855 | 163.0 |
| Average of stations in this region: | 2697 | 2909 | 213 | 2340 | 2532 | 192 | 1793 | 1950 | 157 |
Watch Jeff Andresen's weekly agricultural weather forecast reports
More information and reports on normal weather conditions and departures from normal can be found on the NOAA Climate Prediction Center website, NOAA U.S. Climate Normals website, NOAA Climate Normals Quick Access Page (which may be searched by region), and Midwest Regional Climate Center website.
This work is supported by the Crop Protection and Pest Management Program (grant no 2024-70006-43569) from the USDA National Institute of Food and Agriculture. Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the view of the U.S. Department of Agriculture.
