Southeast Michigan fruit update – May 26, 2026
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EmailStrawberry harvest is starting soon, and blueberry bloom is still going.
Welcome to the ninth 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
Rain that came through in the last week should have ejected most of the remaining primary scab spores, meaning we are moving out of primary scab season. Generally warm temperatures have continued. The return of warm weather has brought out many of the insects that had become less active, with increased catches of codling moth and oriental fruit moth and continued catches of plum curculio and San Jose scale.
The weather will fluctuate this week with a mix of cool and warm temperatures and scattered showers and storms. The main disease we’re concerned about this week is apple powdery mildew, which thrives in warm, humid (but not wet) conditions. With consistent conditions we will move right into the typical cover spray schedule for the season.
Many of you will have already done spring weed control, but if not, this 2020 article on spring herbicide applications from Michigan State University Extension lists some available options.
This year, our weekly integrated pest management (IPM) updates have returned to the 2023 and 2024 format of Tuesday evening virtual meetings covering both small fruit and tree fruit in southeast and southwest Michigan. You can register online at 2026 South Michigan Fruit IPM Updates. It is a good opportunity to hear from experts, ask questions and receive restricted use pesticide (RUP) credits. See the latest weekly fruit meetings for southern Michigan on MSU’s Kaltura Media Space (these may take a few days to upload after the meetings are held).
Fruit-by-fruit conditions
Apples: Apples in the region are sizing up, with considerable variation in diameter depending on region and cultivar. Some growers in cooler areas may still have time for chemical thinning.
Blueberries: We are seeing petal fall with fruit set in cultivars like Bluecrop and Jersey and in cooler parts of the region we are still in full bloom.
Brambles: We are seeing full bloom in summer raspberries, 8-12-inch shoot growth in fall raspberries, and the first floral buds emerging in blackberries.
Cherries: We are seeing fruit set in both tart and sweet cherries in most areas. The cool, extended bloom period along with frosts may result in low crop set in some farms. Cherry pits are starting to harden.
Grapes: We are seeing shoot growth over 12 inches in juice grapes with inflorescence elongation while hybrid wine grapes are closer to 6-8-inch growth. We have yet to see wild grape bloom. Prepare for black rot sprays as bloom approaches.
Peaches and nectarines: Peaches are sizing up in the first growth phase. At some sites in the region there is fruit set from secondary bloom.
Pears: Pears observed in Hartland were at fruit set with Bartlett at 12 mm. There seems to be a wide variation in bloom patterns depending on cultivar and the specific locations of farms.
Plums: Japanese style plums still in the initial growth phase and some are starting to get to the pit hardening phase, while European style plums are in their initial growth phase.
Strawberries: Fruit are sizing up along with continued bloom in strawberries in the region. Some growers in the warmest areas are expecting to start harvest this weekend. Some areas have seen frost damage.
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).
The Trevor Nichols Research Center trapline saw first catches in spotted wing drosophila, dogwood borer, obliquebanded leafroller, variegated leaf roller and cherry fruitworm.
Aphids: Populations are climbing in apple (rosy apple aphid, woolly apple aphid).
Codling moth: A provisional biofix has been set for May 8 at Romeo. Larvicidal products can be used starting about 250 GDD base 50 after biofix (around June 7 in Romeo).
European apple sawfly: Catches have been climbing in southeast Michigan. This is a pest that wasn’t an issue for many years but growers have been reporting damage in the last few seasons.
Grape berry moth: Assess fields for wild grape bloom (V. rupestris), which is the biofix for grape berry moth.
Oriental fruit moth: Biofix was set in Romeo for April 22 (April 13 in Fennville). Numbers are up, but the control window has passed for this generation in most of the region (see the Enviroweather model with biofix).
Pear psylla: More nymphs have been caught in southeast Michigan, but many have been taken care of by cover sprays.
Plum curculio: Counts have been are back up thanks to warm temperatures.
San Jose scale: Additional males have been caught in southeast Michigan and at the Trevor Nichols Research Center. The next time to control is when crawlers emerge in early summer.
Tumid gallmaker: Galls can be found in many locations. If the scope is limited it won’t cause many problems, but if it becomes widespread products like Assail can be used for control.
Disease conditions
Apple scab: The RimPro model for Romeo indicated that the last spore ejection for primary scab took place in the last week. From this point on, growers with existing scab infections should focus on controlling secondary scab. We are not expecting high risk this week.
Cherry leaf spot: We are not expecting high cherry leaf spot risk in the next week. See this 2024 article on cherry leaf spot management.
Fire blight: Since we have moved out of bloom, there is low blossom blight risk in apples and pears. Growers should check for shoot 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. Risk is expected to be low this week.
Grape downy mildew: We are not expecting measurable risk this week.
Grape powdery mildew: We are not expecting measurable risk this week.
Mummy berry: We are in the primary season for mummy berry infections. See E2846 for control methods.
Phomopsis: In blueberries, the Phomopsis fungus is active from bud swell until after harvest.
Powdery mildew of apple and pear: You can start to include products labeled for powdery mildew in sprays starting at tight cluster. We are expecting moderate to high risk from May 29-June 2.
Seasonal weather update
In the last week, southeast Michigan has seen on average of about 12.6 hours of rain accumulating to roughly 0.6 of precipitation.
| Liquid Precipitation Accumulation Mar. 1- May 26, 2026, issued May 26, 2026 | ||||
|---|---|---|---|---|
| Station (County) | Rainfall Total (in.) Current | Hours with Rainfall Current | Rainfall Total Average (5 Yr.) | Hours with Rainfall Average (5 Yr.) |
| Commerce (Oakland) | 11.5 | 160 | 6.8 | 149 |
| Deerfield (Monroe) | 12.0 | 171 | 7.5 | 152 |
| East Lansing MSU Hort (Ingham) | 11.8 | 159 | 7.4 | 153 |
| Emmett (St. Clair) | 10.5 | 169 | 6.6 | 142 |
| Flint (Genesee) | 11.7 | 164 | 7.2 | 155 |
| Freeland (Saginaw) | 10.7 | 147 | . | . |
| Hudson (Lenawee) | 11.1 | 172 | 7.4 | 151 |
| Ithaca (Gratiot) | 13.1 | 159 | 6.7 | 144 |
| Lapeer (Lapeer) | 11.3 | 169 | 6.3 | 153 |
| Linwood (Bay) | 11.7 | 172 | 6.3 | 137 |
| Pigeon (Huron) | 9.8 | 171 | 5.7 | 145 |
| Richville/Frankenmuth (Tuscola) | 11.5 | 158 | 7.1 | 140 |
| Romeo (Macomb) | 10.6 | 147 | 6.8 | 141 |
| Sandusky (Sanilac) | 9.8 | 148 | 6.2 | 139 |
| Average of stations in this region: | 11.2 | 161.9 | 6.8 | 146.2 |
| Difference in Liquid Precipitation Accumulation from Mar. 1 observed May 19 and May 26, 2026; issued May 26, 2026 | ||||||
|---|---|---|---|---|---|---|
| Rainfall Total (in.) | Rainfall Total (in.) | Hours with Rainfall | Hours with Rainfall | |||
| Station (County) | 19-May | 26-May | Difference | 19-May | 26-May | Difference |
| Commerce (Oakland) | 10.5 | 11.5 | 1.1 | 147 | 160 | 13.0 |
| Deerfield (Monroe) | 11.5 | 12.0 | 0.4 | 160 | 171 | 11.0 |
| East Lansing MSU Hort (Ingham) | 11.0 | 11.8 | 0.8 | 146 | 159 | 13.0 |
| Emmett (St. Clair) | 9.8 | 10.5 | 0.8 | 149 | 169 | 20.0 |
| Flint (Genesee) | 11.1 | 11.7 | 0.6 | 152 | 164 | 12.0 |
| Freeland (Saginaw) | 10.4 | 10.7 | 0.3 | 139 | 147 | 8.0 |
| Hudson (Lenawee) | 10.6 | 11.1 | 0.4 | 157 | 172 | 15.0 |
| Ithaca (Gratiot) | 12.4 | 13.1 | 0.6 | 150 | 159 | 9.0 |
| Lapeer (Lapeer) | 10.9 | 11.3 | 0.4 | 154 | 169 | 15.0 |
| Linwood (Bay) | 11.3 | 11.7 | 0.5 | 160 | 172 | 12.0 |
| Pigeon (Huron) | 9.4 | 9.8 | 0.4 | 161 | 171 | 10.0 |
| Richville/Frankenmuth (Tuscola) | 11.1 | 11.5 | 0.4 | 147 | 158 | 11.0 |
| Romeo (Macomb) | 9.5 | 10.6 | 1.2 | 132 | 147 | 15.0 |
| Sandusky (Sanilac) | 9.5 | 9.8 | 0.3 | 135 | 148 | 13.0 |
| Average of stations in this region: | 10.6 | 11.2 | 0.6 | 149.2 | 161.9 | 12.6 |
In the short term, we are expecting warm and dry conditions with a slight cool down to the 70s mid-week warming back up to the 80s on the weekend. Lows will be in the 50s for most of the next week and we don’t expect risk for frost. In the medium term, we are expecting drier and warmer conditions than normal.
Our regional average growing degree day accumulation for the season is about seven to 10 days ahead of the long-term normals and about four days ahead of the five-year average. In the last week, we accumulated on average 116 GDD at 48 F, 98 GDD at 45 F and 67 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-May 26, 2026 Forecast from May 27- June 2, 2026; issued May 26, 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) | 779 | 722 | 939 | 628 | 579 | 767 | 419 | 385 | 523 |
| Deerfield (Monroe) | 959 | 856 | 1120 | 785 | 696 | 925 | 534 | 475 | 639 |
| East Lansing MSU Hort (Ingham) | 859 | 769 | 1017 | 700 | 620 | 837 | 475 | 417 | 578 |
| Emmett (St. Clair) | 682 | 685 | 820 | 544 | 546 | 661 | 355 | 359 | 439 |
| Flint (Genesee) | 829 | 790 | 987 | 676 | 640 | 813 | 460 | 434 | 562 |
| Freeland (Saginaw) | 691 | 715 | 841 | 552 | 575 | 680 | 358 | 385 | 452 |
| Hudson (Lenawee) | 887 | 784 | 1047 | 725 | 636 | 863 | 496 | 434 | 599 |
| Ithaca (Gratiot) | 772 | 762 | 932 | 624 | 615 | 762 | 416 | 416 | 521 |
| Lapeer (Lapeer) | 789 | 741 | 938 | 644 | 598 | 773 | 441 | 404 | 535 |
| Linwood (Bay) | 586 | 627 | 728 | 455 | 498 | 576 | 282 | 326 | 370 |
| Pigeon (Huron) | 596 | 627 | 738 | 468 | 497 | 589 | 294 | 326 | 380 |
| Richville/Frankenmuth (Tuscola) | 747 | 748 | 898 | 624 | 603 | 762 | 416 | 404 | 521 |
| Romeo (Macomb) | 770 | 722 | 920 | 620 | 577 | 748 | 412 | 380 | 507 |
| Sandusky (Sanilac) | 651 | 670 | 784 | 516 | 535 | 628 | 332 | 355 | 411 |
| Average of stations in this region: | 757 | 730 | 908 | 612 | 587 | 742 | 406 | 393 | 503 |
| Difference in Degree Day Accumulation from Mar. 1, 2026 observed May 19 and May 26, 2026; issued May 26, 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 |
| 19-May | 26-May | Difference | 19-May | 26-May | Difference | 19-May | 26-May | Difference | |
| Commerce (Oakland) | 657 | 779 | 122.0 | 526 | 628 | 102.0 | 348 | 419 | 71.0 |
| Deerfield (Monroe) | 824 | 959 | 135.0 | 670 | 785 | 115.0 | 452 | 534 | 82.0 |
| East Lansing MSU Hort (Ingham) | 731 | 859 | 128.0 | 592 | 700 | 108.0 | 399 | 475 | 76.0 |
| Emmett (St. Clair) | 575 | 682 | 107.0 | 455 | 544 | 89.0 | 293 | 355 | 62.0 |
| Flint (Genesee) | 706 | 829 | 123.0 | 572 | 676 | 104.0 | 387 | 460 | 73.0 |
| Freeland (Saginaw) | 576 | 691 | 115.0 | 457 | 552 | 95.0 | 293 | 358 | 65.0 |
| Hudson (Lenawee) | 756 | 887 | 131.0 | 614 | 725 | 111.0 | 417 | 496 | 79.0 |
| Ithaca (Gratiot) | 658 | 772 | 114.0 | 529 | 624 | 95.0 | 353 | 416 | 63.0 |
| Lapeer (Lapeer) | 672 | 789 | 117.0 | 546 | 644 | 98.0 | 372 | 441 | 69.0 |
| Linwood (Bay) | 484 | 586 | 102.0 | 373 | 455 | 82.0 | 229 | 282 | 53.0 |
| Pigeon (Huron) | 502 | 596 | 94.0 | 393 | 468 | 75.0 | 246 | 294 | 48.0 |
| Richville/Frankenmuth (Tuscola) | 632 | 747 | 115.0 | 508 | 624 | 116.0 | 339 | 416 | 77.0 |
| Romeo (Macomb) | 649 | 770 | 121.0 | 518 | 620 | 102.0 | 340 | 412 | 72.0 |
| Sandusky (Sanilac) | 551 | 651 | 100.0 | 435 | 516 | 81.0 | 278 | 332 | 54.0 |
| Average of stations in this region: | 641 | 757 | 116 | 513 | 612 | 98 | 339 | 406 | 67 |
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.
