Southwest Michigan apple maturity report – September 23, 2026
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EmailGolden Delicious and Jonagold are mature this week. Cooler temperatures this week should drive more color development, but it’s important to harvest at the right maturity.
Apple maturity testing will occur weekly for the southwest region beginning now through the end of harvest. Reports will be sent out every week following the Michigan State University Extension fruit team apple maturity calls on Wednesday mornings.
Weather
Cooler conditions have settled across southwest Michigan this week. Wednesday will remain mostly cloudy with a brief shower possible and highs in the mid-60s. Drier weather is expected Thursday through Saturday, with mostly sunny conditions and highs near 70 degrees Fahrenheit. Overnight lows will fall into the upper 40s to low 50s through the weekend. These cool nights and relatively mild, sunny days should favor red color development in apples while providing generally favorable harvest conditions. A small chance for showers returns Sunday, with warmer temperatures expected early next week.
How to read maturity tables
Each week, an apple maturity report will be provided and will include average values for several apple samples for varieties nearing maturity. Maximum and minimum values are included in tables below for the highest and lowest individual fruits evaluated for each, to give a full spectrum of maturity. Samples included in the reports have been untreated with ReTain or Harvista, unless otherwise noted. Samples were collected from 1-2 locations in Berrien and Van Buren counties.
For more information about apple maturity testing, review these resources compiled by the MSU Extension tree fruit team.
- Predicted apple harvest dates for 2026 from MSU.
- More information on harvest management tools and timings can be found in this article.
- Guidelines from MSU to check for apple maturity in your own orchard, including specific pressure and starch recommendations by variety.
- New starch charts for evaluating apple maturity in Michigan from Michigan State University
- Predicting apple maturity and starch chart from Cornell University.
- Starch chart for Honeycrisp Apples developed by Washington State University.
Maturity information for the Southwest Region
Golden Delicious
Golden Delicious fruit were sampled from one location in Berrien County on Tuesday. Red color (blush on Goldens) is at 0%, and background color is green-yellow at 3.1. Fruit firmness is at 16.9 lbs of pressure. Starch is an average of 4.5. Sugars are an average of 12.9 °Brix. Golden Delicious has reached maturity and harvest is underway.
|
Collection Date |
Fruit Weight (g) |
Red Color (%) |
Background color (5-1) |
Firmness (lbs) |
Starch |
Soluble Solids (°Brix) |
|
Sep 22 |
232.3 |
0 (0.0–0.0) |
3.1 (3.0–4.0) |
16.9 (15.6–18.3) |
4.5 (4.0–7.0) |
12.9 |
Jonagold
Jonagold fruit were sampled from one location in Van Buren County on Tuesday. Red color is at 47%, and background color is green-yellow at 3.3. Fruit firmness is at 14.8 lbs of pressure. Starch is an average of 5.9. Sugars are an average of 15.8 °Brix. Jonagold has reached maturity and should be harvested promptly where fruit remain.
|
Collection Date |
Fruit Weight (g) |
Red Color (%) |
Background color (5-1) |
Firmness (lbs) |
Starch |
Soluble Solids (°Brix) |
|
Sep 22 |
314.8 |
47.0 (20.0–65.0) |
3.3 (2.0–4.0) |
14.8 (13.7–17.6) |
5.9 (4.0–7.0) |
15.8 |
Mutsu
Mutsu fruit were sampled from one location in Van Buren County on Tuesday. Red color is at 2%, and background color is green at 3.9. Fruit firmness is at 18.1 lbs of pressure. Starch is an average of 1.6. Sugars are an average of 13.9 °Brix. Mutsu is immature this week.
|
Collection Date |
Fruit Weight (g) |
Red Color (%) |
Background color (5-1) |
Firmness (lbs) |
Starch |
Soluble Solids (°Brix) |
|
Sep 22 |
320.2 |
2.0 (0.0–5.0) |
3.9 (3.0–5.0) |
18.1 (15.5–21.4) |
1.6 (1.0–3.0) |
13.9 |
Northern Spy
Northern Spy fruit were sampled from one location in Van Buren County on Tuesday. Red color is at 5.2%, and background color is green at 4.9. Fruit firmness is at 19.1 lbs of pressure. Starch is an average of 2.1. Sugars are an average of 12.7 °Brix. Spys are immature this week.
|
Collection Date |
Fruit Weight (g) |
Red Color (%) |
Background color (5-1) |
Firmness (lbs) |
Starch |
Soluble Solids (°Brix) |
|
Sep 22 |
242.0 |
5.2 (0.0–20.0) |
4.9 (4.0–5.0) |
19.1 (17.3–20.9) |
2.1 (1.0–3.0) |
12.7 |
Evercrisp
Evercrisp fruit were sampled from one location in Van Buren County on Tuesday. Red color is at 62.5%, and background color is green at 4.8. Fruit firmness is at 20.6 lbs of pressure. Starch is an average of 1.5. Sugars are an average of 14.5 °Brix. Evercrisp is immature this week.
|
Collection Date |
Fruit Weight (g) |
Red Color (%) |
Background color (5-1) |
Firmness (lbs) |
Starch |
Soluble Solids (°Brix) |
|
Sep 22 |
286.0 |
62.5 (40.0–80.0) |
4.8 (4.0–5.0) |
20.6 (18.9–23.0) |
1.5 (1.0–2.0) |
14.5 |
Apple maturity sampling parameters
- Color % = the visual percentage of red color from 0 to 100; range is of all fruits tested. Indicates surface area covered in red and intensity of red color.
- Background color: 5 = Green, 1 = Yellow; range is of all fruits tested.
- Firmness in pounds pressure = measured with a Güss Fruit Texture Analyzer; range is of all fruits tested.
- Starch For Honeycrisp: will typically be rated using the standard Michigan State University starch scale (1-8). However, a separate starch chart for Honeycrisp Apples developed by Washington State University (scale 1-6) also exists.
- Brix = % sugar measured with Atago PAL-1 Pocket Refractometer
Looking for more? View Michigan State University Extension’s Apple page for regional reports throughout the state and additional resources.
|
Suggested firmness and starch index levels for long-term and shorter-term controlled atmosphere (CA) storage by variety. |
|||||
|---|---|---|---|---|---|
|
Variety |
Firmness (pounds)* |
Starch Index* |
|||
|
Short CA |
Mid-CA |
Long CA |
Mature |
Over mature |
|
|
McIntosh |
14 |
15 |
16 |
5 |
7 |
|
Gala |
16 |
17 |
18 |
3 |
6 |
|
Honeycrisp |
15 |
16 |
17 |
3.5 |
6 |
|
Empire |
14 |
15 |
16 |
3.5 |
6 |
|
Early Fuji |
16 |
17 |
18 |
3 |
7 |
|
Jonagold |
15 |
16 |
17 |
3.5 |
5.5 |
|
Jonathan |
14 |
15 |
16 |
3.5 |
5.5 |
|
Golden Delicious |
15 |
16 |
17 |
3 |
6.5 |
|
Red Delicious |
16 |
17 |
18 |
2.5 |
6 |
|
Idared |
14 |
15 |
16 |
3.5 |
6 |
|
Fuji |
16 |
17 |
18 |
3 |
7 |
|
Rome |
15 |
16 |
18 |
3 |
5.5 |
|
Brix Guide |
Low |
Fair |
Good |
Excellent |
|
All varieties |
Less than 11 |
11 |
12 |
13 |
|
Honeycrisp |
Less than 12 |
12 |
12 |
Greater than 14 |
