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Pinxterbloom azalea

Rhododendron periclymenoides

Ericaceae · [VERIFY] · native

Last updated

Data Coverage 3 of 6 dimensions
Site Data
Threats
Cultivars
Phenology
GDD Thresholds
Puget Sound

Pinxterbloom azalea (Rhododendron periclymenoides) is a deciduous shrub in the Ericaceae family reaching 3-6 ft tall with a 4-7 ft spread. It produces showy pink to white flowers and attracts hummingbirds and butterflies.

Detailed site preferences and cultivation data require further enrichment from authoritative sources. All parts are poisonous to humans, cats, dogs, and horses. The plant shares the general Ericaceae preference for acidic, well-drained soil in partial shade.

Quick Facts

Height
3–6 ft
Spread
4–7 ft
Growth Rate
Slow
Light
[Verify]
Soil
[Verify]
Water
[verify]
Hardiness
Zone Zone [VERIFY]
Bloom Time
april to may
Origin
eastern North America

Phenological Calendar

Regional Season Tracker

GDD₃₂ accumulation across 7 Puget Sound stations · as of Mar 30, 2026
Station GDD₃₂ Current Stage Next To Go
Issaquah / East King 1,116 Pre-season Full bloom 504
Seattle / UW 1,112 Pre-season Full bloom 508
Olympia / Tumwater 1,049 Pre-season Full bloom 572
Kent / Auburn 1,048 Pre-season Full bloom 572
Bellingham / Whatcom 1,041 Pre-season Full bloom 579
Tacoma / Puyallup 1,017 Pre-season Full bloom 603
Sequim / Rain Shadow 1,012 Pre-season Full bloom 608
Stage GDD32 Typical Window
○ Full bloom BBCH 65 NEXT 1620 — est. Apr 29 (avg)
Regional estimate
Range: 849–1031 GDD₃₂ (6yr)

GDD = Growing Degree Days (base 32°F, Jan 1 start). Why base 32? Source GDD₅₀ thresholds from Herms 2004 (OSU, Secrest Arboretum, Ohio) and UMD IPMnet (Gill & Klick, mid-Atlantic), converted to GDD₃₂ via Kent bloom-date mapping. Season tracker for Kent / Auburn as of Mar 30, 2026. Predicted dates use 16-day weather forecast through Apr 15, 2026, then climate normals.