MSU Extension Apples

The information below includes predicted dates for peak harvest. Actual harvest dates may begin before and extend after these dates, and it is likely to vary based on specific location and conditions. This information is intended to be used by commercial growers to start planning harvest management. Interpretation is necessary for marketing purposes and fruit may be available in retail locations at different times.

The predicted harvest dates for all Michigan State University Enviroweather Stations are now available online and can be determined using the Apple Maturity Model on the Enviroweather Website. These models for McIntosh, Jonathan and Red Delicious calculate predict harvest dates based on full bloom date and the temperatures in the 30 days after bloom.

Most varieties appear to be a week or more ahead of normal harvest dates. Harvest dates may need to be adjusted as we get closer to harvest.

Crop load. Blocks with light crop loads will mature 3 or 4 days sooner than the predicted harvest dates while heavy crop loads will mature up to a week later than the predicted dates.

Conditions during August and September will also affect harvest dates. If hot stressful weather occurs in August or September, apple maturity will be advanced, especially in early to mid-ripening cultivars.

Stop-drop materials. ReTain application should be applied 21 to 28 DBH (days before harvest), depending on the variety and season. Harvista can be applied 3 to 7 DBH. Use Table 3, 2024 Predicted Harvest Dates for Other Varieties, to time ReTain applications and adjust for varieties and locations.

The tables below list the normal and predicted harvest dates for varieties across the state. Table 1 lists the predicted harvest dates for locations across the state of Michigan for 2024. Table 2 lists this year’s predictions compared to normal and last year. Table 3 lists the normal harvest dates for other varieties for the Ridge area with focus on Sparta. This year's predicted dates for other non-modeled varieties are a rough estimate based on the McIntosh, Jonathan and Red Delicious predicted dates and historical experience in the area.

*Dates indicated by model, not by actual observation.

 * - is days earlier, + is days later than normal

*Normal harvest dates in this table were determined from average observations by industry members in the region.

Thanks to Amy Irish-Brown of Valent USA for her help in this summary.