West central Michigan tree fruit update – April 30, 2025

Emily Lavely<lavelyem@msu.edu>, Michigan State University Extension - April 30, 2025

Warmer weather means bud phenology is moving right along. Apricots are in full bloom, and plum and sweet cherry are beginning to bloom.

Figure 1. Apricot trees in full bloom in Hart, Michigan, on April 28, 2025. Photo by Emily Lavely, MSU Extension.

Weather update

Warm weather led to many changes in bud development over the last few days across the west central and Grand Rapids, Michigan, regions. Apricots are in full bloom (Figure 1) with sweet cherry and plum starting early bloom in some regions. Warmer day and nighttime temperatures in the west central region means there is a lot of new leaf growth, and bloom will be around the corner for cherry, apple, pear and peach (Figure 2). Early apple varieties, such as Smitten, are in early bloom in the Grand Rapids region, and later varieties like Paula Red are at pink.

Based on the Hart Enviroweather station for April 29, current degree-day (DD) accumulation is 266 DD42 and 109 DD50. Across the region, DD accumulation is now above the five-year average for the Hart (Table 1) and Sparta (Table 2) Enviroweather stations.

For the Hart and Sparta Enviroweather stations, temperatures will cool down this week with highs in the 50s and 60s and lows in the 30s and 40s. Some areas may experience temperatures close to freezing this week. Rain is also in the forecast for the end of the week in the west central and Grand Rapids regions.

Watch a full weather update from Jeff Andresen, Michigan State University (MSU) climatologist. 

FIG2 CAPTION: Figure 2. Stage of tree phenology for apple, pear, cherry, peach and apricot in Oceana County on April 28, 2025. Photo by Emily Lavely, MSU Extension.

Table 1. West central region: Current and 5-year average degree days summary for base 42 F and base 50 F for weather stations in the west central region from Jan. 1 – April 29.

Station	2025 DD Base 42 F	5-yr Avg DD Base 42 F	2025 DD Base 50 F	5-yr Avg DD Base 50 F
Benona/Shelby	236	221	93	88
Elbridge/Hart	276	259	119	110
Fremont	304	280	136	118
Grant	350	310	164	137
Hart	266	254	109	106
Ludington	251	245	98	103
Mears	266	254	109	107
New Era	257	246	105	99
Shelby-East	272	250	116	104

Table 2. Grand Rapids region: Current and 5-year average degree days summary for base 42 F and base 50 F for weather stations in the Grand Rapids region from Jan. 1 – April 29.

Station	2025 DD Base 42 F	5-yr Avg DD Base 42 F	2025 DD Base 50 F	5-yr Avg DD Base 50 F
Sparta	350	307	163	135
Alpine Twp/ Comstock Park	362	320	169	141
Sparta-North	341	307	153	133
Conklin/Wright	346	311	157	135
Kent City	332	297	127	104
Standale/Walker	389	352	187	161
Belding	355	315	165	142
Clarksville	387	335	183	151

Weather data was gathered from MSU Enviroweather.

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.

Crop update

With warmer temperatures and sunny days, growers have been working through early season tasks such as pruning trees, chopping brush, planting trees and installing trellis. Windy conditions have made spraying difficult, but winds should die down tonight and provide a spray window tomorrow to cover trees before the rain on Thursday.

In the west central region, apple varieties in Oceana County range from tight cluster to early pink. Early varieties such as Zestar and Idared are at early pink, and later varieties such as Gala and Honeycrisp are at tight cluster. In the Grand Rapids area, early varieties such as Smitten are at early bloom. Later varieties such as Paula Red are at pink.

Tart and sweet cherry buds range from tight cluster to first bloom. For tart cherries, bract leaves are starting to emerge and tissue will become susceptible to cherry leaf spot.

Peaches are at green calyx and red calyx depending on the variety. Venture peach at the West Central Michigan Research and Extension Center are at red calyx.

Pear varieties are at tight cluster for Bartlett pear at the West Central Michigan Research and Extension Center.

Pest and disease update

West central area report

With warmer temperatures and more rapid bud development, emerging tissue in apple is at risk for apple scab infection. In New Era, Michigan, there was a short rain on April 21, and 49 spores per rod were trapped. However, with the warmer temperatures and more spores maturing to be ready for release, new tissue will need to be protected through fungicide coverage. Through the rest of the week, there are high and extreme infection risks predicted for apple scab with rain in the forecast toward the end of the week in the Hart area. I will continue to check the spore trap and monitor spore release.

For cherry leaf spot, bract leaves are emerging in Montmorency tart cherry at the West Central Michigan Research and Extension Center with the warmer temperatures. It’s time to put on the first cherry leaf spot fungicide spray if bract leaves are showing in your orchard blocks.

In Oceana County, green fruitworm (12 adults per trap) and red banded leafroller (43 adults per trap) were trapped this week. Black stem borer were trapped at the end of last week in Oceana County, and they were trapped this week in Mason County.

Grand Rapids area report

Information provided by Amy Irish-Brown, Valent U.S.A

Tree fruit diseases. From the very light rain events on April 20 and 22 for the Sparta Enviroweather station, there were a total of four apple scab spores per rod. Neither of these wetting events were infections and rainfall totals were very, very light across the whole Grand Rapids region. The big story for scab this week is at least 50% of the ascospores are now mature and just waiting for a rain event to discharge. Tree growth is moving along, so make sure new foliage is always protected. The next three or four weeks will be critical for all tree fruit disease management – apple scab, powdery mildew and fire blight. Be preventative with your disease sprays, stay ahead of the infections, and cover new growth as needed. Powdery mildew does not need actual rainfall to infect as scab does—high relative humidity is what really drives early mildew infections. Add mildewcides for the next few weeks to be covered.

Tree fruit insects. Pink sprays for apples are needed soon if not done already in more southern areas. Know your pest complex and use the material(s) that cover you for that pressure. Be mindful of bees present in neighboring orchards, particularly stone fruits that are already blooming. Insects typically targeted at pink in apple include aphids (all species), San Jose scale, apple rust mites, green fruitworm (which has been higher in recent years), red banded leafroller (minor pest) and spotted tentiform leafminer (minor pest). Oriental fruit moth will start to fly soon, so get traps placed, but controls come later. Small overwintering obliquebanded leafroller larvae will also be found soon, but these can be targeted with DiPel when they start to be found, even during bloom.

Similar to last week, researchers at the Trevor Nichols Research Center reported trapping red banded leafroller and plum curculio. No green fruitworm were trapped this week. The first catch of oriental fruit moth occurred with 2.7 moths per trap.

For more information about regional reports, please visit the Michigan State University Extension website.

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