Peaches in the southern regions are post-bloom and some at shuck split, with warm temperatures ramping up some vigorous growth.

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Phenology This Week

This week is an abbreviated report due to the Spring Orchard Meetings that begin this evening at Stauffer's Fruit Farm & Market in Denver, PA. The dates and locations of these meetings are provided here, and though walk-ins are always welcome at these free meetings, advance registration through the Penn State Extension website is always preferred so we can plan ahead.

2025 Spring Orchard Meeting Schedule

Tuesday, April 29, 6:00 - 8:30 p.m.

Lancaster / York Counties
Stauffer's Fruit Farm
430 Panorama Drive
Denver

Wednesday, April 30, 6:00 - 8:30 p.m.

Adams County
Kuhn's Orchard
1041 Old Route 30
Orrtanna

Thursday, May 1, 6:00 - 8:30 p.m.

Franklin County
Andrews Farm Market
896 Apple Way
St. Thomas

Tuesday, May 6, 6:00 - 8:30 p.m.

Berks County
Brecknock Orchards
390 Orchard Road
Mohnton

Wednesday, May 7, 6:00 - 8:30 p.m.

Central Susquehanna / Northeastern Region
Greens Fruit Farm
574 Sleepy Hollow Road
Elysburg

Thursday, May 8, 6:00 - 8:30 p.m.

Appalachian Region / Centre County
Harner Farm
2191 West Whitehall Road
State College

Wednesday, May 14, 6:00 - 8:30 p.m.

Western Region
Rivendale Farms
1357 Valleyview Road
Bulger

Thursday, May 15, 10:00 - 11:30 a.m.

Erie / Northwestern Region
Burch Farms
9210 Sidehill Road
Northeast

Note that all meetings begin at 6:00 p.m. except for the Erie location, which begins at 10:00 a.m. Signage will direct visitors to where the programs begin. Extension greatly appreciates the willingness of the hosts to open their farms and markets to the public for these events.

Phenology Data

Growing Degree Day Accumulation

**Table 1.** Growing Degree Day (GDD)
County	Weather Station	GDD43˚F	GDD50˚F
Adams	Biglerville (Penn State FREC)	523	248
Berks	Boyertown	466	210
Centre	Rock Spring (Penn State Orchard)	347	155
Erie	Harborcreek	320	137
Franklin	Orrtanna^*	525	251

Data taken from NEWA using the Degree Day Type of "Base 43 ℉" and "Base 50 ℉" between the dates of 1/1/2025 and 4/28/2025. The Orrtanna* station is closest to the orchard from where weekly data are collected.

Apple Bloom Phenology

Most varieties in the Southeastern and Southcentral regions, and some in Centre county, are at or beyond the petal fall stage. There are exceptions depending on variety and location, as seen in Figure 1, of two (unfortunately) unknown varieties adjacent to one another at the Adams County (Gettysburg) Extension Office.

The photo depicts two clusters of flowers (left) and fruitlets (right). These photos were taken at the same day and time, with the trees planted within six feet of one another. One the left is a blossom cluster at full bloom stage. On the right, the cluster has past petal fall and fruitlets are beginning to swell. — Figure 1. Two clusters of blossoms and fruitlets. The tree on the left is entirely in full bloom, while the tree on the right is well past petal fall, with the fruit beginning to swell.

This chart documents the standard bud stage names for apple blossom development and lists the temperatures at which there is 10% and 90% bud kill after a 30-minute exposure to the given temperatures. Use it to interpret the bud stages in the tables below, and to monitor potential damage in your apple orchards when frost or freeze events are expected.

This is a chart listing the standard names for apple bud / blossom stages and the critical temperatures that kill 10% and 90% of blossom after 30 minutes of exposure. — Figure 2. Fruit stages sourced from the Utah State Extension fact sheet "Critical Temperatures for Frost Damage on Fruit Trees." Images used by permission of the author, Marion Murray, Utah State University.

**Table 2.** Phenology estimations based on observations made on the morning of April 28, 2025, for Apple Varieties. (Erie data will be updated when it comes in.)
County	Fuji	Gala	Golden Delicious	Honeycrisp	Pink Lady®	Red Delicious
Adams	Petal Fall	Petal Fall	Post Bloom	Petal Fall	Post Bloom	Post Bloom
Berks	Petal Fall	Petal Fall	Petal Fall	Petal Fall	Petal Fall	Petal Fall
Centre	King Bloom Petal Fall	60% Bloom	Full Bloom	70% Bloom	King Bloom Petal Fall	--
Erie	--	--	--	--	--	--
Lawrence	90% Bloom	Full Bloom	80% Bloom	Full Bloom	Full Bloom	Full Bloom

Peach Bloom Phenology

This chart documents the standard bud stage names for apple blossom development and lists the temperatures at which there is 10% and 90% bud kill after a 30-minute exposure to the given temperatures. Use it to interpret the bud stages in the tables below, and to monitor potential damage in your apple orchards when frost or freeze events are expected.

This is a chart listing the standard names for peach bud / blossom stages and the critical temperatures that kill 10% and 90% of blossom after 30 minutes of exposure. — Figure 3. Fruit stages sourced from the Utah State Extension fact sheet "Critical Temperatures for Frost Damage on Fruit Trees." Images used by permission of the author, Marion Murray, Utah State University.

**Table 3.** Peach varieties observed per county on April 28^th, segregated by approximate harvest period.
County	Early Variety	Early Stage	Mid Variety	Mid Stage	Late Variety	Late Stage
Adams	Desiree®	Shuck Split	John Boy®	Shuck Split	Coralstar®	Post Bloom/Shuck Split
	Sentry	Shuck Split	--	--	Messina®	Post Bloom/Shuck Split
	SilverGlo™	Shuck Split	--	--	--	--
Berks	--	--	Redhaven	Post Bloom	Messina®	Post Bloom
Centre	Redhaven	Post Bloom	--	--	--	--
Franklin	Desiree®	Post Bloom	Contender	Post Bloom	Bounty	Post Bloom
	Glenglo™	Post Bloom	John Boy®	Post Bloom	Messina®	Post Bloom
	--	--	Redhaven	Post Bloom	--	--
Lawrence	--	--	Redhaven	Post Bloom	Autumnstar®	Post Bloom
	--	--	--	--	Coralstar®	Post Bloom

Additional Discussion

The state of apple and peach development in Pennsylvania will be covered at the Twilight Meetings where a good discussion about thinning strategies is guaranteed to happen. Extension hopes to see you there.

Agenda

Authors