P.J.M. Rhododendron
Rhododendron pjm
Ericaceae · broadleaf evergreen shrub · introduced
Last updated
Data Maturity Structured
This profile synthesizes data from multiple published sources. Expert field review is in progress.
Quick Facts
Height
3–6 ft
Water
Moderate
Hardiness
Zone Zones 4a–8b
Phenological Calendar
As of April 23, 2026, Puget Sound stations range from 1434.4 to 1592.7 GDD₃₂. P.J.M. Rhododendron has passed 'full bloom' (1032 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 | 'Full bloom' | — | — |
| Seattle / UW | 1,554 | 'Full bloom' | — | — |
| Kent / Auburn | 1,537 | 'Full bloom' | — | — |
| Olympia / Tumwater | 1,505 | 'Full bloom' | — | — |
| Bellingham / Whatcom | 1,483 | 'Full bloom' | — | — |
| Tacoma / Puyallup | 1,472 | 'Full bloom' | — | — |
| Sequim / Rain Shadow | 1,434 | 'Full bloom' | — | — |
| Stage | GDD32 | Typical Window |
|---|---|---|
| 'First bloom' BBCH '61' | 853 | '' |
| ● 'Full bloom' BBCH '65' NOW | 1032 | '' |
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 10, 2026, then climate normals.
Diseases (22)
Root Rot (Phytophthora spp.) Multiple obligate biotrophic fungi (Erysiphales: Erysipha... Powdery Mildew Ovulinia azaleae Ovulinia Petal Blight Lime-induced Chlorosis Symptom category — not a single disease Leaf Spot Exobasidium vaccinii Leaf and Flower Gall Cylindrocladium scoparium Cylindrocladium Blight and Root Rot Botrytis Petal Blight Xylella fastidiosa Marginal leaf necrosis Rhododendron and Cutting Rots Leaf Burn abiotic (drought, heat stress) or bacterial (Xylella fast... Leaf Scorch Ramorum Blight (Sudden Oak Death) Botryosphaeria dothidea Botryosphaeria Dieback Seifertia azaleae Bud Blight Rhododendron necrotic ringspot virus Necrotic Ringspot Thekopsora minima and Naohidemyces vaccinii Rust Taphrina wiesneri Witches' Broom Armillaria ostoyae Armillaria Root Rot Pestalotiopsis sydowiana Gray Blight Physiological leaf spot Phytophthora Blight
Pests (21)
Tetranychidae Spider mite Otiorhynchus spp. Root weevil Choristoneura rosaceana Obliquebanded Leafroller Caloptilia azaleella Azalea leafminer Stephanitis pyrioides Azalea Lace Bug Acanthococcus azaleae Azalea bark scale Salt injury Sunburn Tissue Proliferation Aphidoidea Aphid Lepidoptera Caterpillars Parthenolecanium spp. Lecanium scale Stephanitis rhododendri Rhododendron lace bug Dialeurodes chittendeni Rhododendron whitefly Nematus lipovskyi Azalea sawfly Tingidae Lace bug Stephanitis spp. Azalea and rhododendron lace bug Cacoecimorpha pronubana Carnation tortrix Icerya purchasi Cottony cushion scale Coleotechnites huntella Rhododendron bud moth Nematode, Stunt