Elizabeth Rhododendron

Rhododendron 'Elizabeth'

Ericaceae · broadleaf evergreen shrub · introduced

Last updated April 22, 2026

Data Maturity Structured

This profile synthesizes data from multiple published sources. Expert field review is in progress.

Well-suited to Puget Sound maritime conditions. Common in residential landscapes; the low, spreading habit works well as a foundation plant or in woodland gardens. Tolerates the cool, moist climate but needs good drainage; clay soil sites typical of the Green River valley require raised beds or amendment. Susceptible to root weevil damage (noted by OSU). 'Elizabeth' is widely available at PNW nurseries. Observed in bloom at Issaquah 2026-04-20.

— Chris Welch, ISA Certified Arborist

Quick Facts

Height

3-4 ft

Spread

4-5 ft

Growth Rate

Slow

Light

Part Shade

Soil

Well Drained

Water

Moderate

Hardiness

Zone Zones 7a–9a

Bloom Time

Apr 1-Apr 25

Origin

Hybrid: R. forrestii subsp. forrestii Repens Group × R.

Phenological Calendar

Stage	Typical Window	What to Look For
Bud swell BBCH 01-03	Mar 1-Mar 25	Terminal flower buds enlarging, showing color through scales; vegetative buds remain tight
Bloom start BBCH 61	Apr 1-Apr 25	First scarlet-red trumpet flowers opening in lax trusses
Full bloom BBCH 65	Apr 10-May 5	Peak display; trusses fully open, scarlet-red trumpets covering the plant
Bloom end BBCH 69	Apr 25-May 15	Flowers fading and dropping; spent trusses brown and papery
New growth flush BBCH 11-15	May-Jun	Bright green (or burgundy-red on 'Elizabeth') new growth emerging after bloom; this is the wood that sets next year's flower buds
Flower bud set BBCH 55	Jul-Aug	Terminal buds plumping at branch tips; larger and rounder than vegetative buds
Summer rebloom (sporadic) BBCH 61	Aug-Sep	Occasional flowers on some trusses; characteristic of 'Elizabeth' but not reliable every year

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