Southeast Michigan fruit update – September 15, 2026
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EmailMain apple harvest season underway. Waiting on fall weather.
Welcome to the 25th 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
Last weekend's warm temperatures slowed crowds at orchards and cider mills and this weekend rain might do the same. We are expecting cool and cloudy conditions mid-week followed by a rain starting Saturday and lasting into next week. Growers are continuing mid-season apples and grapes. Powdery mildew is again the biggest disease risk this week along with sooty blotch.
Regional and statewide apple maturity reports have started. MSU Extension educators recently published the 2026 apple maturity prediction tables, including the apple harvest prediction dates for southeast Michigan.
Fruit-by-fruit conditions
Apples: While we are harvesting many cultivars, it is important to remember that some late cultivars may need an additional fungicide treatment. In warmer parts of the region, growers are finishing up Spartan, continuing Cortland and Jonathan, and starting Empire apples for fresh market sales. Coloring has been slow on varieties like ‘Empire’ and Honeycrisp, so some farms are waiting to harvest or extending the picking window.
Statewide apple maturity reports started last week and can be read at our apple maturity hub. Our main concerns at this time of year are powdery mildew, apple maggot, brown marmorated stink bug and codling moth. Pay attention to pre-harvest intervals for any spray applied at this time of year.
Blueberries: The main harvest season has wrapped up.
Brambles:Fall raspberry and blackberry harvests continue, though blackberry is getting towards the end of its season. 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. Growers should still pay attention to cherry leaf spot management.
Grapes:In Southeast Michigan several cultivars have already been harvested. In hybrid wine grapes we are through Frontenac Blanc and Prairie Star with Frontenac and Petite Pearl harvest in sight. In table grapes growers are working through Mars. Concord and Fredonia harvest continues. Growers should also monitor for spotted lanternfly, which has been found in the region.
Peaches and nectarines: Harvest has come to an end.
Pears: Pears should be picked when they start to soften and the ground color changes from green to a more yellow color.
Plums: European style plum harvest has concluded with Stanley and Damson plums making it to market.
Strawberries: Harvest is done in the region and most growers have already renovated.
Insect conditions
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).
Apple maggot: Counts at Fennville have remained stable with less than 1 per trap.
Blueberry maggot: Numbers remain low in Fennville with less than 1 per trap.
Borers: Catch of greater peach tree borer of lesser peachtree borer are down in Fennville with less than 1 per trap.
Brown marmorated stink bug: BMSB adults along with damage have been observed in Southeast Michigan orchards. Because adults are active so close to harvest you need to pay close attention to your pre-harvest intervals.
Codling moth: Adult catches have declined again in Fennville with 1.7 per trap compared to 4.3 last week.
Grape berry moth: Counts in Fennville have dropped to 0 from 3 last week.
Japanese beetle: Counts remain low in Fennville.
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 put out webbing.
Oriental fruit moth: Counts have remained stable around 9 per trap in Fennville.
San Jose scale: Counts of adult males in Fennville have dropped to around 4 per trap.
Spotted lanternfly: Look for nymphs or adults in parts of the state that have documented populations (Detroit, Monroe County, Oakland County).
Disease conditions
Apple scab: We don’t anticipate risk for secondary scab infections on fruit this week.
Cherry leaf spot: We anticipate slight to moderate risk this week from September 16-18. See this 2024 article on cherry leaf spot management.
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 downy mildew: We anticipate medium to moderate risk on September 16-18.
Grape powdery mildew: We are expecting slight to severe risk all week.
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 and models indicate moderate to severe risk all week.
Sooty blotch: We don’t anticipate risk this week.
Seasonal weather update
In the last week, Southeast Michigan has seen an average of 5.1 hours of rain accumulating to 0.2 inches of precipitation.
| Liquid Precipitation Accumulation Mar. 1- September 15, 2026, issued September 15, 2026 | ||||
|---|---|---|---|---|
| Station (County) | Rainfall Total (in.) Current | Hours with Rainfall Current | Rainfall Total Average (5 Yr.) | Hours with Rainfall Average (5 Yr.) |
| Commerce (Oakland) | 21.8 | 280 | 20.5 | 292 |
| Deerfield (Monroe) | 25.7 | 274 | 18.5 | 279 |
| East Lansing MSU Hort (Ingham) | 22.3 | 306 | 18.7 | 285 |
| Emmett (St. Clair) | 20.7 | 324 | 18.7 | 290 |
| Flint (Genesee) | 20.1 | 284 | 20.4 | 301 |
| Freeland (Saginaw) | 20.7 | 253 | . | . |
| Hudson (Lenawee) | 21.6 | 288 | 17.9 | 282 |
| Ithaca (Gratiot) | 21.7 | 290 | 18.0 | 276 |
| Lapeer (Lapeer) | 20.6 | 312 | 19.2 | 309 |
| Linwood (Bay) | 21.7 | 294 | 17.3 | 275 |
| Pigeon (Huron) | 19.4 | 291 | 16.6 | 285 |
| Richville/Frankenmuth (Tuscola) | 22.1 | 275 | 19.3 | 290 |
| Romeo (Macomb) | 22.3 | 288 | 21.6 | 283 |
| Sandusky (Sanilac) | 19.8 | 283 | 16.5 | 325 |
| Average of stations in this region: | 21.5 | 288.7 | 18.7 | 289.3 |
| Difference in Liquid Precipitation Accumulation from Mar. 1 observed September 1 and September 15, 2026; issued September 15, 2026 | ||||||
|---|---|---|---|---|---|---|
| Rainfall Total (in.) | Rainfall Total (in.) | Hours with Rainfall | Hours with Rainfall | |||
| Station (County) | 8-Sep | 15-Sep | Difference | 8-Sep | 15-Sep | Difference |
| Commerce (Oakland) | 21.3 | 21.8 | 0.5 | 270 | 280 | 10.0 |
| Deerfield (Monroe) | 25.6 | 25.7 | 0.0 | 272 | 274 | 2.0 |
| East Lansing MSU Hort (Ingham) | 21.7 | 22.3 | 0.6 | 297 | 306 | 9.0 |
| Emmett (St. Clair) | 20.5 | 20.7 | 0.2 | 316 | 324 | 8.0 |
| Flint (Genesee) | 20.0 | 20.1 | 0.1 | 280 | 284 | 4.0 |
| Freeland (Saginaw) | 20.6 | 20.7 | 0.0 | 250 | 253 | 3.0 |
| Hudson (Lenawee) | 21.5 | 21.6 | 0.1 | 286 | 288 | 2.0 |
| Ithaca (Gratiot) | 21.6 | 21.7 | 0.1 | 283 | 290 | 7.0 |
| Lapeer (Lapeer) | 20.4 | 20.6 | 0.2 | 304 | 312 | 8.0 |
| Linwood (Bay) | 21.7 | 21.7 | 0.0 | 292 | 294 | 2.0 |
| Pigeon (Huron) | 19.4 | 19.4 | 0.0 | 291 | 291 | 0.0 |
| Richville/Frankenmuth (Tuscola) | 22.1 | 22.1 | 0.0 | 272 | 275 | 3.0 |
| Romeo (Macomb) | 21.9 | 22.3 | 0.4 | 281 | 288 | 7.0 |
| Sandusky (Sanilac) | 19.7 | 19.8 | 0.1 | 277 | 283 | 6.0 |
| Average of stations in this region: | 21.3 | 21.5 | 0.2 | 283.6 | 288.7 | 5.1 |
In the short term we are expecting cool and cloudy conditions mid-week with temperatures staying in the mid-70s and increasing into the 80s on the weekend. We are expecting above normal temperatures and normal precipitation as we move into September and we expect a fall that is warmer and drier than normal.
Our regional average growing degree day accumulation for the season are about 7 days ahead of the long term normals and about 3 days ahead of the 5 year average. In the last week we accumulated on average 165 GDD at 42 F, 157 GDD at 45 F, and 111 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-Sep. 8, 2026 Forecast from Sep. 16-Sep. 22, 2026; issued Sep. 15, 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) | 3906 | 3697 | 4073 | 3419 | 3221 | 3565 | 2655 | 2480 | 2766 |
| Deerfield (Monroe) | 4210 | 3993 | 4390 | 3700 | 3501 | 3589 | 2895 | 2735 | 3019 |
| East Lansing MSU Hort (Ingham) | 3974 | 3745 | 4135 | 3480 | 3264 | 3620 | 2704 | 2520 | 2809 |
| Emmett (St. Clair) | 3619 | 3463 | 3776 | 3147 | 2993 | 3284 | 2413 | 2267 | 2515 |
| Flint (Genesee) | 4091 | 3892 | 4257 | 3602 | 3408 | 3747 | 2883 | 2654 | 2942 |
| Freeland (Saginaw) | 3759 | 3683 | 3904 | 3285 | 3210 | 3409 | 2359 | 2476 | 2629 |
| Hudson (Lenawee) | 4034 | 3836 | 4214 | 3539 | 3358 | 3698 | 2762 | 2617 | 2887 |
| Ithaca (Gratiot) | 3996 | 3850 | 4149 | 3511 | 3370 | 3643 | 2748 | 2620 | 2845 |
| Lapeer (Lapeer) | 3854 | 3650 | 4010 | 3377 | 3178 | 3512 | 2629 | 2447 | 2729 |
| Linwood (Bay) | 3449 | 3433 | 3591 | 2985 | 2972 | 3106 | 2267 | 2261 | 2353 |
| Pigeon (Huron) | 3574 | 3516 | 3709 | 3111 | 3502 | 3225 | 2383 | 2336 | 2462 |
| Richville/Frankenmuth (Tuscola) | 3861 | 3746 | 4013 | 3882 | 3267 | 3513 | 2629 | 2520 | 2726 |
| Romeo (Macomb) | 3955 | 3742 | 4121 | 3469 | 3263 | 3614 | 2706 | 2516 | 2816 |
| Sandusky (Sanilac) | 3713 | 3571 | 3859 | 3423 | 3104 | 3368 | 2507 | 2382 | 2597 |
| Average of stations in this region: | 3857 | 3701 | 4014 | 3388 | 3226 | 3512 | 2619 | 2488 | 2712 |
| Difference in Degree Day Accumulation from Mar. 1, 2026 observed September 8 and September 15, 2026; issued September 15, 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 |
| 8-Sep | 15-Sep | Difference | 8-Sep | 15-Sep | Difference | 8-Sep | 15-Sep | Difference | |
| Commerce (Oakland) | 3737 | 3906 | 169.0 | 3271 | 3419 | 148.0 | 2542 | 2655 | 113.0 |
| Deerfield (Monroe) | 4035 | 4210 | 175.0 | 3546 | 3700 | 154.0 | 2775 | 2895 | 120.0 |
| East Lansing MSU Hort (Ingham) | 3807 | 3974 | 167.0 | 3334 | 3480 | 146.0 | 2591 | 2704 | 113.0 |
| Emmett (St. Clair) | 3465 | 3619 | 154.0 | 3014 | 3147 | 133.0 | 2313 | 2413 | 100.0 |
| Flint (Genesee) | 3918 | 4091 | 173.0 | 3450 | 3602 | 152.0 | 2714 | 2883 | 119.0 |
| Freeland (Saginaw) | 3600 | 3759 | 159.0 | 3146 | 3285 | 139.0 | 2433 | 2389 | 106.0 |
| Hudson (Lenawee) | 3866 | 4034 | 168.0 | 3391 | 3539 | 148.0 | 2648 | 2762 | 114.0 |
| Ithaca (Gratiot) | 3830 | 3996 | 166.0 | 3366 | 3511 | 145.0 | 2636 | 2748 | 112.0 |
| Lapeer (Lapeer) | 3691 | 3854 | 163.0 | 3234 | 3377 | 143.0 | 2519 | 2629 | 110.0 |
| Linwood (Bay) | 3301 | 3449 | 148.0 | 2856 | 2985 | 129.0 | 2169 | 2267 | 98.0 |
| Pigeon (Huron) | 3407 | 3574 | 167.0 | 2965 | 2985 | 146.0 | 2271 | 2383 | 112.0 |
| Richville/Frankenmuth (Tuscola) | 3695 | 3861 | 166.0 | 3237 | 3111 | 145.0 | 2518 | 2629 | 111.0 |
| Romeo (Macomb) | 3781 | 3955 | 174.0 | 3316 | 3382 | 153.0 | 2591 | 2706 | 115.0 |
| Sandusky (Sanilac) | 3551 | 3713 | 162.0 | 3103 | 3469 | 320.0 | 2400 | 2507 | 107.0 |
| Average of stations in this region: | 3692 | 3857 | 165 | 3231 | 3388 | 157 | 2509 | 2619 | 111 |
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.
