Southeast Michigan fruit update – May 13, 2025

Blueberries and strawberries are blooming and in fruit set.

Blueberries blooming at Spicer Orchards in Hartland, Michigan, on May 12, 2025. Photo by Derek Plotkowski, MSU Extension.

Welcome to the sixth in-season fruit article update for southeast Michigan for the 2025 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 

Despite projections of warmer and drier weather, we have seen continued rain in the region. Mixed with warm temperatures, this wetness can contribute to disease and it’s important as ever to get ahead of diseases with multiple generations, like scab. The coming week is expected to start with more rain with warmer temperatures followed by a cool-down. With the potential for storms coming through Thursday, May 15, it may be helpful to read through this Michigan State University Extension article on responding to hail and severe storms. 

This year, our weekly integrated pest management (IPM) updates will be separated into two meetings: a small fruit meeting for southern Michigan on Tuesday evenings (register for small fruit IPM meetings) and a statewide tree fruit IPM update on Wednesdays at noon (register for tree fruit IPM meetings). It is a good opportunity to hear from experts, ask questions and receive restricted use pesticide (RUP) credits. See the latest fruit meetings for southern Michigan on MSU’s Kaltura Media Space (these may take a few days to upload after the meetings are held) at the small fruit channel and the tree fruit channel.  

Fruit-by-fruit conditions 

Apples 

We are seeing petal fall and fruit set in early varieties like Zestar while even later varieties like Northern Spy are seeing petal fall. Some varieties are seeing a protracted bloom, where flowers take a longer time to fall off. In a protracted bloom, trees are at greater risk for fire blight. 

Apple_Zestar_Tollgate_May12_2025.JPEG

Zestar apple blossoms at the Tollgate Farm in Novi, Michigan, on May 12, 2025. Photo by Derek Plotkowski, MSU Extension. 

Blueberries 

We are seeing full bloom in some early blueberry varieties with later varieties starting their first bloom. At bloom we see damage when temperatures drop to 28 degrees Fahrenheit. 

Blueberry_Early_Spicers_May12_2025.JPEG
Blueberries blooming at Spicer Orchards in Hartland, Michigan, on May 12, 2025. Photo by Derek Plotkowski, MSU Extension. 

Brambles 

We are seeing continued shoot growth in summer raspberries and blackberries with a few floral buds emerging in summer raspberries. Fall raspberry shoots have elongated to about 8 inches in Hartland. 

Raspberry_Summer2_Spicers_May12_2025.JPEG
Raspberry floral bud in Hartland, Michigan, on May 12, 2025. Photo by Derek Plotkowski, MSU Extension. 

Cherries

We are seeing fruit set in sweet cherries, with fruitlets at 5 millimeters (mm) in Hartland. Tart cherries are still at petal fall with some lingering blossoms.  

Cherry_Sweet_Spicers_May12_2025.JPEG
Sweet cherry at 5 mm fruit set in Hartland, Michigan, on May 12, 2025. Photo by Derek Plotkowski, MSU Extension. 

Grapes 

Bud burst, first leaves and even floral bud exposure have been observed in southeast Michigan. At first leaf the critical temperatures are 27 F for 10% kill and 21 F for 90% kill. 

Grape_Concord_Spicers_May12_2025.JPEG
Concord grape with floral bud exposure in Hartland, Michigan, on May 12, 2025. Photo by Derek Plotkowski, MSU Extension. 

Peaches and nectarines 

Peaches in the region are mostly at petal fall with some lingering bloom. At full bloom the critical temperatures are 27 F for 10% kill and 24 F for 90% kill. 

Peach_Spicers_May12_2025.JPEG
Peach branch in Hartland, Michigan, on May 12, 2025. Photo by Derek Plotkowski, MSU Extension. 

Pears 

Pears in the region are at fruit set, with pears observed in Hartland at 7 mm diameter. 

Pear_Spicers_May12_2025.JPEG
Bartlett pear trees at 7 mm diameter fruit set in Hartland, Michigan, on May 12, 2025. Photo by Derek Plotkowski, MSU Extension. 

Plums 

Italian plums observed in Romeo were at petal fall. 

Plum_Verellen_May13_2025.jpg
Italian plums in Romeo, Michigan, on May 13, 2025. Photo by Derek Plotkowski, MSU Extension. 

Strawberries 

Flowers are starting to become abundant. Treatments during bloom should focus on leaf spot and fruit rots. 

Strawberry_Spicers_May12_2025.JPEG
Strawberry flowers in Hartland, MI on May 12, 2025. Photo by Derek Plotkowski 

Insect conditions 

Pollinators are active in the orchard. This2024 article on pollinator stewardship during bloom in tree fruitand the2021 Blueberry Guide for Pollinator Stewardshipare particularly relevant at this time.   

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). 

Codling moth: Codling moth has been caught in southeast Michigan (biofix set for May 9). Ovicidal products are most effective 100-150 growing degree days base 45 (GDD45) after first adult emergence. See this 2024 article for best management practices. 

Grape berry moth: Green berry moth has been caught at the Trevor Nichols Research Center in Fennville. Read this article on early season grape berry moth control. 

Green fruit worm: No green fruit worm catches in southeast Michigan. Higher catches this week in Fennville. These can be controlled with insecticides post-bloom. 

Oriental fruit moth: Threshold catches of oriental fruit moth have been reported in southeast Michigan while numbers have climbed in Fennville. Ovicidal products are most effective 100-150 GDD45 after first adult emergence. 

Pear psylla: Egg hatch continues to climb. 

Plum curculio: Catches reported in Fennville. None reported yet in southeast Michigan, though they are surely out. 

Redbanded leafroller: Catches are down but remain high in southeast Michigan. 

Spotted tentiform leafminer: Control for spotted tentiform leafminer is usually not necessary, but may be useful in problem areas beginning at tight cluster in apples 

Tarnished plant bug: Tarnished plant bug damage has been seen in the region in addition to catches. Do not mow, disc or mechanically weed during the critical window as the insect can feed on flowers and developing fruit. Control is usually done at petal fall only if the pest is an issue in your orchard. 

Control periods in the warmer parts of the region have passed for black stem borer, mites, scale and rosy apple aphid. 

Disease conditions

Apple scab: There is a forecasted risk for infection from May 14-16. Early control of scab is important for reducing secondary scab infections that can affect fruit. No scab has been reported regionally yet. 

Black knot: There is still time to prune out and burn black knot in plums and sour cherries. Fungicides may be used for limited control to supplement pruning and sanitation efforts. 

Brown rot: Fungicides may be necessary to control if there are high temperatures during bloom, especially in orchards that have had brown rot presence in previous seasons. 

Cherry leaf spot: There is low risk for cherry leaf spot in the next week. See this 2013 article on cherry leaf spot management. 

Fire blight: There is some risk for fire blight in trees with lingering blossoms. No fire blight has been reported regionally yet. 

Grape black rot: Control for grape black rot usually begins at 1-inch shoot length. See this 2014 article for grape black rot management options and consult E0154.  

Mummy berry: We are still in the 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: Some powdery mildew has already been reported in the region. You can start to include products labeled for powdery mildew in sprays starting at tight cluster. There is forecasted risk for infection from May 18-20. 

Seasonal weather update 

In the last week, southeast Michigan has seen on average over 11 hours of rain accumulating to roughly 0.6 inches of precipitation. We are ahead of the five-year average in amount of rainfall. 

Liquid Precipitation Accumulation Mar. 1- May 12, 2025, issued May 12, 2025
Station (County) Rainfall Total (in.) Current Hours with Rainfall Current Rainfall Total Average (5 Yr.) Hours with Rainfall  Average (5 Yr.)
Commerce (Oakland) 7.2 140 6.0 135
Deerfield (Monroe) 8.4 141 6.1 136
East Lansing MSU Hort (Ingham) 8.0 138 6.4 137
Emmett (St. Clair) 6.9 118 5.4 128
Flint (Genesee) 7.8 140 5.9 135
Freeland (Saginaw) 6.3 116 . .
Hudson (Lenawee) 8.7 146 6.1 133
Ithaca (Gratiot) 7.1 128 5.4 127
Lapeer (Lapeer) 7.8 136 4.7 136
Linwood (Bay) 5.5 119 5.6 124
Pigeon (Huron) 4.5 163 5.2 123
Richville/Frankenmuth (Tuscola) 8.4 128 5.1 122
Romeo (Macomb) 8.2 138 5.4 125
Sandusky (Sanilac) 6.2 102 5.2 129
Average of stations in this region: 7.2 132.4 5.6 130.0
Difference in Liquid Precipitation Accumulation from Mar. 1 observed May 5 and May 12, 2025; issued May 12, 2025
  Rainfall Total (in.)  Rainfall Total (in.)    Hours with Rainfall  Hours with Rainfall   
Station (County) 5-May 12-May Difference 5-May 12-May Difference
Commerce (Oakland) 6.7 7.2 0.5 129 140 11.0
Deerfield (Monroe) 7.9 8.4 0.5 128 141 13.0
East Lansing MSU Hort (Ingham) 7.0 8.0 1.0 125 138 13.0
Emmett (St. Clair) 6.6 6.9 0.3 112 118 6.0
Flint (Genesee) 7.1 7.8 0.8 131 140 9.0
Freeland (Saginaw) 5.5 6.3 0.7 106 116 10.0
Hudson (Lenawee) 7.5 8.7 1.2 130 146 16.0
Ithaca (Gratiot) 6.4 7.1 0.7 118 128 10.0
Lapeer (Lapeer) 7.5 7.8 0.3 129 136 7.0
Linwood (Bay) 4.7 5.5 0.7 109 119 10.0
Pigeon (Huron) 4.1 4.5 0.4 137 163 26.0
Richville/Frankenmuth (Tuscola) 7.6 8.4 0.9 118 128 10.0
Romeo (Macomb) 7.6 8.2 0.6 126 138 12.0
Sandusky (Sanilac) 5.8 6.2 0.3 96 102 6.0
Average of stations in this region: 6.6 7.2 0.6 121.0 132.4 11.4

In the short term, we are expecting warm and wet conditions through the end of the week followed by a cool-down on the weekend. Storms may develop Thursday evening into Friday. Lows through the week will be in the 50s followed by 40s on the weekend. Highs will start in the 70s and 80s midweek followed by 60s on the weekend. 

In the medium term, we are expecting temperatures to be cooler than normal with precipitation above normal. This is a change from past weeks where we’ve been expecting warmer and drier conditions. The long lead outlooks are calling for both temperature and precipitation to be near normal. 

In the warmer parts of the region, we are further ahead of the five-year average in growing degree day accumulations while the cooler areas in the northern part of Southeast Michigan have growing degree day numbers very close to the five-year average. Read this Michigan State University Extension article to learn more about degree days: Understanding growing degree-days. 

Degree Day Accumulation Mar. 1-May 12, 2025 Forecast from May 13-May 19, 2025; issued May 12, 2025
Station (County) Degree Days Base 42°F Current Degree Days Base 42°F  Average (4 Yr.) Degree Days Base 42°F Forecast Degree Days Base 45°F Current Degree Days Base 45°F Average (4 Yr.) Degree Days Base 45°F Forecast Degree Days Base 50°F Current Degree Days Base 50°F Average (4 Yr.) Degree Days Base 50°F Forecast
Commerce (Oakland) 522 444 693 411 341 561 259 210 374
Deerfield (Monroe) 632 548 809 504 429 660 331 273 453
East Lansing MSU Hort (Ingham) 558 485 726 440 376 587 279 237 391
Emmett (St. Clair) 452 428 612 348 328 487 213 199 319
Flint (Genesee) 569 497 742 452 387 603 292 245 408
Freeland (Saginaw) 442 441 603 339 340 479 205 211 312
Hudson (Lenawee) 560 487 736 444 379 599 288 241 409
Ithaca (Gratiot) 503 473 665 391 367 533 244 230 352
Lapeer (Lapeer) 524 468 686 414 364 555 265 230 373
Linwood (Bay) 370 376 522 278 284 409 162 171 260
Pigeon (Huron) 364 384 506 271 291 393 157 177 244
Richville/Frankenmuth (Tuscola) 473 470 636 364 365 506 249 227 328
Romeo (Macomb) 505 447 671 393 342 539 247 208 358
Sandusky (Sanilac) 434 406 584 332 310 462 200 190 296
Average of stations in this region: 493 454 657 384 350 527 242 218 348
Difference in Degree Day Accumulation from Mar. 1, 2025 observed May 5 and May 12, 2025; issued May 12, 2025
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 
  5-May 12-May Difference 5-May 12-May Difference 5-May 12-May Difference
Commerce (Oakland) 444 522 78.0 348 411 63.0 217 259 42.0
Deerfield (Monroe) 544 632 88.0 432 504 72.0 282 331 49.0
East Lansing MSU Hort (Ingham) 482 558 76.0 378 440 62.0 238 279 41.0
Emmett (St. Clair) 387 452 65.0 296 348 52.0 180 213 33.0
Flint (Genesee) 487 569 82.0 384 452 68.0 245 292 47.0
Freeland (Saginaw) 367 442 75.0 278 339 61.0 166 205 39.0
Hudson (Lenawee) 479 560 81.0 378 444 66.0 244 288 44.0
Ithaca (Gratiot) 419 503 84.0 323 391 68.0 198 244 46.0
Lapeer (Lapeer) 451 524 73.0 355 414 59.0 226 265 39.0
Linwood (Bay) 310 370 60.0 231 278 47.0 134 162 28.0
Pigeon (Huron) 316 364 48.0 235 271 36.0 136 157 21.0
Richville/Frankenmuth (Tuscola) 403 473 70.0 308 364 56.0 184 249 65.0
Romeo (Macomb) 433 505 72.0 336 393 57.0 210 247 37.0
Sandusky (Sanilac) 372 434 62.0 282 332 50.0 168 200 32.0
Average of stations in this region: 421 493 72 326 384 58 202 242 40

Watch Jeff Andresen's weekly agricultural weather forecast reports here. 

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. 

 

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