Callery Pear
Pyrus calleryana
Rosaceae · broadleaf deciduous tree · introduced
Last updated
This profile synthesizes data from multiple published sources. Expert field review is in progress.
Callery pear ranks among the most common flowering trees in residential and commercial landscapes in the Puget Sound lowlands. It handles the wet winter/dry summer cycle without irrigation once established. Note: increasingly recognized as invasive due to prolific self-seeding from cross-pollinated cultivars. Performs well in local heavy clay soils. One of the first trees to bloom each spring—useful phenological marker for seasonal transition. Primary bacterial disease concern in this region is Pseudomonas blossom blast, NOT fire blight (per WSU: 'Fire blight is not a proven problem in western Washington'). Pear trellis rust is commonly reported where junipers are nearby. Monitor for invasive seedling establishment: cross-pollination between cultivars (especially where multiple cultivars are planted on the same street) can produce fertile offspring.
— HortGuide editorial
Pyrus calleryana (Rosaceae) is a deciduous tree native to China, Vietnam, Korea, and Japan. It grows 30 to 40 feet tall and 15 to 25 feet wide with a pyramidal to oval form. Dense clusters of white flowers appear in early spring, followed by small, hard, brown to black fruit (about 1 cm). Fall color ranges through bronze, orange, purple, red, and yellow.
Callery pear tolerates a remarkable range of urban stresses: heavy clay, compacted soil, poor drainage, pollution, and drought. Originally introduced in 1908 by the USDA as fire blight-resistant rootstock, the cultivar 'Bradford' (released 1962) became one of the most widely planted street trees in the United States. However, cross-pollination among cultivars has produced invasive seedlings that now infest disturbed areas across the eastern U.S. Many communities have restricted or banned new plantings. The species carries 25 documented diseases and 11 pests. Hardy in Zones 4b to 8b.
Quick Facts
Phenological Calendar
As of April 23, 2026, Puget Sound stations range from 1434.4 to 1592.7 GDD₃₂. Callery Pear has passed end of flowering / petal fall (1071 GDD₃₂).
Regional Season Tracker
GDD₃₂ accumulation across 7 Puget Sound stations · as of Apr 23, 2026| Station | GDD₃₂ | Current Stage | Next | To Go |
|---|---|---|---|---|
| Issaquah / East King | 1,593 | End of flowering / petal fall | — | — |
| Seattle / UW | 1,554 | End of flowering / petal fall | — | — |
| Kent / Auburn | 1,537 | End of flowering / petal fall | — | — |
| Olympia / Tumwater | 1,505 | End of flowering / petal fall | — | — |
| Bellingham / Whatcom | 1,483 | End of flowering / petal fall | — | — |
| Tacoma / Puyallup | 1,472 | End of flowering / petal fall | — | — |
| Sequim / Rain Shadow | 1,434 | End of flowering / petal fall | — | — |
| Stage | GDD32 | Typical Window |
|---|---|---|
| Dormancy break / bud swell BBCH 01–03 | 285 | Late Feb – early Mar |
| Green tip / leaf emergence BBCH 10 | 475 | Early – mid Mar |
| Beginning of flowering BBCH 61 | 713 | Mid – late Mar |
| Full bloom BBCH 65 | 864 | Late Mar – mid Apr |
| ● End of flowering / petal fall BBCH 69 NOW | 1071 | Mid – late Apr |
| Fruit development BBCH 71 | — | May – Jun |
| Leaf senescence BBCH 93 | — | Oct – early Nov |
| Dormancy BBCH 97 | — | Nov – Feb |
GDD = Growing Degree Days (base 32°F, Jan 1 start). Why base 32? Hover over GDD values for source details. Season tracker for Kent / Auburn as of Apr 23, 2026. Predicted dates use 16-day weather forecast through May 9, 2026, then climate normals.