Southeast Michigan fruit update – July 21, 2026
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EmailBlueberries and peaches continue; Dealing with smoke, cyclospora and Japanese Beetles.
Welcome to the 17th 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
In the last week, we have experienced continued high heat and humidity but without much rain besides scattered storms. We have also been experiencing the effects of wildfire smoke and poor air quality- you can read this recent MSU Extension article on staying safe during air quality alerts, which is important for farm workers and anyone who works outside. We are expecting the next week to be cooler than the last, with some rain coming in on Sunday into Monday.
Blueberry harvest is continuing while peaches are ramping up. Red Haven is looking to be ready in the Romeo area sometime around August 1, reaching its peak while summer raspberries are starting to wind down. Powdery mildew is again the biggest disease risk this week and spotted wing drosophila continues to be a concern in berry crops. At this point in the season for apples we are continuing the normal pattern of summer cover sprays.
Japanese beetle populations are still high in the region and we recently published a new article about controlling the pest in orchards and vineyards. The Cyclospora outbreak in the country continues. While this does not appear to be linked to Michigan farms, this is a good opportunity to review on-farm produce safety guidelines and this MSU Extension video How to Keep Cyclospora from Ruining Your Season.
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 apple cultivars like ‘Lodi’ and ‘Yellow Transparent’ are being harvested. Our main concerns at this time of year are powdery mildew, apple maggot and codling moth.
Blueberries: The main harvest season continues. Spotted wing drosophila and fruit rot management are priorities.
Brambles: Harvest is starting to wind down in summer raspberries and black raspberries. Some initial blackberry harvest has started. Flowers are just starting to open in fall raspberries. 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: Grapes are sizing up, with tight-clustered varieties at bunch closure.
Peaches and nectarines: Harvest of early cultivars continues. We are expecting ‘Red Haven’ harvest in the Romeo area to start around August 1. For mid-to-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”
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 Japanese-style plums like ‘Early Golden’ are already being harvested.
Strawberries: Harvest is done in the region. Thrips damage was extensive in certain parts of the state. Many areas have also seen frost damage, resulting in lower crops at some farms. Some growers have started renovating their fields for next year. You can read more in this article on renovation. Most tank mixes are safe and effective when allowed by the label, but some combinations (e.g. 2,4-D with a graminicide or a fast-acting contact herbicide with glyphosate) can result in reduced effectiveness. Check your labels for tank-mix restrictions and crop safety.
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).
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.
Apple maggot: First catch was reported in southeast Michigan three weeks ago with some additional catches this week. None have been reported in Fennville yet.
Blueberry maggot: Counts are down again this week in Fennville.
Borers: Similar catch to last week of greater peachtree borer and a decrease in lesser peachtree borer have been reported in Fennville.
Cranberry fruit worm: Counts at Fennville are stable and low.
Codling moth: Adult catches are down regionally. We are likely between generations.
Grape berry moth: Growers observed wild grape bloom the first week of June, which is the biofix for grape berry moth. Counts at Fennville are up again from last week to this week.
Japanese beetle: Counts have been climbing regionally. Kaolin clay can be a deterrent and perimeter sprays can also be effective for keeping them under control.
Mites: With hot and dry conditions the last couple of weeks, mite populations have climbed. European red mites and rust mites are starting to cause some bronzing in orchards. Two spotted spider mites have started webbing in spots that have existing populations.
Oriental fruit moth: Counts have risen at sites in southeast Michigan, indicating that we may be starting the next generation. Counts are down in Fennville.
Pear psylla: Increased adult and nymph activity has been observed in orchards again.
San Jose scale: We are seeing waxed-up scales in the region, meaning that 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: The RimPro model for Romeo indicates that primary scab season is over. From this point on growers with existing scab infections should focus on controlling secondary scab. We do not anticipate risk this week.
Cherry leaf spot: We do not anticipate risk this week. See this 2024 article on cherry leaf spot management.
European brown rot: Stone fruits are susceptible to infection around three weeks after shuck split and again three 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. There is not much risk for black rot this week and grape bloom is mostly done. 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 do not anticipate risk this week.
Grape powdery mildew: We are expecting severe risk for the entire week.
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 severe risk for the entire week.
Seasonal weather update
In the last week, Southeast Michigan has seen an average of 1.4 hours of rain accumulating to 0.2 inches of precipitation.
| Liquid Precipitation Accumulation Mar. 1- July 21, 2026, issued July 21, 2026 | ||||
| Station (County) | Rainfall Total (in.) Current | Hours with Rainfall Current | Rainfall Total Average (5 Yr.) | Hours with Rainfall Average (5 Yr.) |
| Commerce (Oakland) | 16.2 | 219 | 13.2 | 234 |
| Deerfield (Monroe) | 18.9 | 213 | 13.6 | 227 |
| East Lansing MSU Hort (Ingham) | 16.6 | 228 | 13.7 | 229 |
| Emmett (St. Clair) | 16.6 | 244 | 13.6 | 229 |
| Flint (Genesee) | 15.3 | 224 | 14.1 | 240 |
| Freeland (Saginaw) | 16.5 | 201 | . | . |
| Hudson (Lenawee) | 16.9 | 231 | 13.6 | 232 |
| Ithaca (Gratiot) | 18.2 | 223 | 12.1 | 217 |
| Lapeer (Lapeer) | 15.1 | 235 | 13.8 | 237 |
| Linwood (Bay) | 18.0 | 233 | 12.1 | 216 |
| Pigeon (Huron) | 15.8 | 240 | 11.4 | 224 |
| Richville/Frankenmuth (Tuscola) | 17.4 | 215 | 12.7 | 215 |
| Romeo (Macomb) | 17.4 | 216 | 15.6 | 226 |
| Sandusky (Sanilac) | 15.1 | 214 | 11.8 | 237 |
| Average of stations in this region: | 16.7 | 224.0 | 13.2 | 227.9 |
| Difference in Liquid Precipitation Accumulation from Mar. 1 observed July 14 and July 21, 2026; issued July 21, 2026 | ||||||
| Rainfall Total (in.) | Rainfall Total (in.) | Hours with Rainfall | Hours with Rainfall | |||
| Station (County) | 14-Jul | 21-Jul | Difference | 14-Jul | 21-Jul | Difference |
| Commerce (Oakland) | 16.2 | 16.2 | 0.0 | 219 | 219 | 0.0 |
| Deerfield (Monroe) | 18.4 | 18.9 | 0.5 | 211 | 213 | 2.0 |
| East Lansing MSU Hort (Ingham) | 16.6 | 16.6 | 0.0 | 228 | 228 | 0.0 |
| Emmett (St. Clair) | 16.4 | 16.6 | 0.2 | 242 | 244 | 2.0 |
| Flint (Genesee) | 15.3 | 15.3 | 0.1 | 223 | 224 | 1.0 |
| Freeland (Saginaw) | 16.3 | 16.5 | 0.1 | 199 | 201 | 2.0 |
| Hudson (Lenawee) | 16.8 | 16.9 | 0.1 | 229 | 231 | 2.0 |
| Ithaca (Gratiot) | 18.2 | 18.2 | 0.0 | 223 | 223 | 0.0 |
| Lapeer (Lapeer) | 15.1 | 15.1 | 0.0 | 234 | 235 | 1.0 |
| Linwood (Bay) | 17.9 | 18.0 | 0.1 | 231 | 233 | 2.0 |
| Pigeon (Huron) | 15.8 | 15.8 | 0.0 | 239 | 240 | 1.0 |
| Richville/Frankenmuth (Tuscola) | 16.8 | 17.4 | 0.6 | 214 | 215 | 1.0 |
| Romeo (Macomb) | 16.7 | 17.4 | 0.7 | 214 | 216 | 2.0 |
| Sandusky (Sanilac) | 14.4 | 15.1 | 0.7 | 210 | 214 | 4.0 |
| Average of stations in this region: | 16.5 | 16.7 | 0.2 | 222.6 | 224.0 | 1.4 |
In the short term, we are expecting the next week to be cooler than the last, with temperatures peaking in the mid-70s midweek and then climbing into the mid-80s over the weekend. Some showers and storms are possible Sunday into Monday. Overnight lows will be in the 50s midweek and climb into the 60s by the weekend. In the next month, we are expecting August to exhibit normal temperatures and below normal precipitation.
Our regional average growing degree day accumulation for the season is about seven days ahead of the long-term normals and about three days ahead of the 5-year average. In the last week we accumulated on average 224 GDD at 42 degrees Fahrenheit, 202 GDD at 45 F, and 167 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-July 21, 2026 Forecast from July 22-28, 2026; issued July 21, 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) | 2327 | 2199 | 2522 | 2008 | 1890 | 2182 | 1524 | 1425 | 1663 |
| Deerfield (Monroe) | 2605 | 2431 | 2798 | 2263 | 2105 | 2436 | 1737 | 1612 | 1874 |
| East Lansing MSU Hort (Ingham) | 2408 | 2266 | 2600 | 2081 | 1952 | 2253 | 1583 | 1479 | 1719 |
| Emmett (St. Clair) | 2140 | 2087 | 2324 | 1837 | 1783 | 2000 | 1380 | 1328 | 1508 |
| Flint (Genesee) | 2446 | 2331 | 2643 | 2125 | 2015 | 2301 | 1634 | 1538 | 1775 |
| Freeland (Saginaw) | 2231 | 2215 | 2120 | 1924 | 1909 | 2092 | 1455 | 1447 | 1587 |
| Hudson (Lenawee) | 2503 | 2336 | 2700 | 2175 | 2023 | 2350 | 1674 | 1550 | 1814 |
| Ithaca (Gratiot) | 2402 | 2319 | 2597 | 2085 | 2006 | 2259 | 1600 | 1532 | 1739 |
| Lapeer (Lapeer) | 2293 | 2184 | 2482 | 1983 | 1878 | 2151 | 1512 | 1418 | 1645 |
| Linwood (Bay) | 2029 | 2040 | 2213 | 1731 | 1744 | 1894 | 1286 | 1302 | 1414 |
| Pigeon (Huron) | 2070 | 2063 | 2269 | 1774 | 1767 | 1953 | 1326 | 1325 | 1469 |
| Richville/Frankenmuth (Tuscola) | 2310 | 2263 | 2499 | 1999 | 1952 | 2167 | 1524 | 1480 | 1657 |
| Romeo (Macomb) | 2343 | 2216 | 2537 | 2025 | 1904 | 2198 | 1542 | 1435 | 1681 |
| Sandusky (Sanilac) | 2172 | 2110 | 2359 | 1870 | 1810 | 2036 | 1412 | 1362 | 1543 |
| Average of stations in this region: | 2306 | 2219 | 2476 | 1991 | 1910 | 2162 | 1514 | 1445 | 1649 |
| Difference in Degree Day Accumulation from Mar. 1, 2026 observed July 14 and July 21, 2026; issued July 21, 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 |
| 14-Jul | 21-Jul | Difference | 14-Jul | 21-Jul | Difference | 14-Jul | 21-Jul | Difference | |
| Commerce (Oakland) | 2096 | 2327 | 231.0 | 1798 | 2008 | 210.0 | 1349 | 1524 | 175.0 |
| Deerfield (Monroe) | 2371 | 2605 | 234.0 | 2050 | 2263 | 213.0 | 1559 | 1737 | 178.0 |
| East Lansing MSU Hort (Ingham) | 2179 | 2408 | 229.0 | 1874 | 2081 | 207.0 | 1410 | 1583 | 173.0 |
| Emmett (St. Clair) | 1927 | 2140 | 213.0 | 1644 | 1837 | 193.0 | 1222 | 1380 | 158.0 |
| Flint (Genesee) | 2205 | 2446 | 241.0 | 1905 | 2125 | 220.0 | 1449 | 1634 | 185.0 |
| Freeland (Saginaw) | 2014 | 2231 | 217.0 | 1728 | 1924 | 196.0 | 1294 | 1455 | 161.0 |
| Hudson (Lenawee) | 2276 | 2503 | 227.0 | 1969 | 2175 | 206.0 | 1503 | 1674 | 171.0 |
| Ithaca (Gratiot) | 2166 | 2402 | 236.0 | 1870 | 2085 | 215.0 | 1420 | 1600 | 180.0 |
| Lapeer (Lapeer) | 2071 | 2293 | 222.0 | 1782 | 1983 | 201.0 | 1346 | 1512 | 166.0 |
| Linwood (Bay) | 1826 | 2029 | 203.0 | 1549 | 1731 | 182.0 | 1139 | 1286 | 147.0 |
| Pigeon (Huron) | 1867 | 2070 | 203.0 | 1592 | 1774 | 182.0 | 1179 | 1326 | 147.0 |
| Richville/Frankenmuth (Tuscola) | 2091 | 2310 | 219.0 | 1800 | 1999 | 199.0 | 1361 | 1524 | 163.0 |
| Romeo (Macomb) | 2111 | 2343 | 232.0 | 1815 | 2025 | 210.0 | 1367 | 1542 | 175.0 |
| Sandusky (Sanilac) | 1963 | 2172 | 209.0 | 1682 | 1870 | 188.0 | 1259 | 1412 | 153.0 |
| Average of stations in this region: | 2083 | 2306 | 223 | 1790 | 1991 | 202 | 1347 | 1514 | 167 |
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.
