Scientific Name:
Rhododendron
(evergreen spp. & cvs.)
Pronunciation:
roe-doe-DEN-drun
Common Name:
rhododendron
Family Name:
Ericaceae
Plant Type:
Broadleaf evergreen
Key ID Features:
Leaves alternate, usually leathery, mostly elliptic, 2-20cm long x 1-7cm wide, petioles 5-20mm long; flowers up to 5cm wide; corolla deeply 5-lobed, stamens 10.
Habit:
Dense, Spreading, Upright
Form:
Oval - vertical
Texture:
Coarse
Mature Height:
7 - 10m
Mature Spread:
4 - 5m
Growth Rate:
Slow
Origin:
Garden origin, North America
Hardiness Rating:
Zone 6: (-23 to -18 °C)
Exposure:
Part sun/part shade, Filtered shade, Deep shade
Soil/Growing Medium:
Humus rich, Well-drained
Water Use:
Low
Landscape Uses:
Group or mass planting, Mixed shrub border, Screening, Specimen plant, Tall background, Woodland margin (Caution: poisonous parts)
Additional Info:
Google. Species shown may include
R. arizelum,
R. formosanum,
R. fortunei, and
R. macrophyllum (see separate entries for other species and cultivars on campus). Description of common cultivars can be found at Monrovia.com.
Leaf Morphology:
Form:
Simple
Arrangement:
Alternate
Texture/Venation:
Leathery
Surfaces:
Glabrous
Colour in Fall:
Green
Shapes:
Elliptic
Apices:
Acuminate, Acute
Bases:
Attenuate, Obtuse
Margins:
Entire
Inflorescence Type:
Raceme, Floriferous
Flower Morphology:
Flowers perfect
Number Of Petals:
5
Corolla Shape:
Campanulate
Ovary Position:
Superior
Colour (petals):
Showy, White, Orange, Yellow, Purple, Pink, Red, Dark-red
Flower Scent:
None
Flower Time at Peak:
May
Fruit Type:
Capsule
Fruit Colour:
Brown
Fruiting Time:
Aug, Sep
Additional Info:
Not showy, Persistent,
Bark or Stem Colour:
Leaf Bud Type:
Striate scales (Outer scale centered directly over leaf scar)
Leaf Scar Shape:
Crescent shaped
Organ Modifications:
Fibrous-like roots, Forms a shallow tap root system when grown from seed
Propagation:
Seed, Softwood cuttings, Layering
Maintenance:
Low
Other:
Most hybrid cultivars will not form capsules (many gardeners find these unattractive and spend time removing them each spring).
Pest Susceptibility:
Abiotic disorder, Aphids or adelgids, Beetles or weevils, Blight or needle cast, Fungal leaf spot, Galls, Heteroptera - true bugs, Mildew, Root rot, Rust (Rabbit resistant)
Specific Pests:
Course(s):
- HORT 1155
- Level 3 Apprenticeship
Location(s):
- (GAZ) GAZebo
- (GAZE) GAZebo East : cv. Blue Diamond
- (GAZW) GAZebo West : cv. Blue Diamond
- (HPZ) Horticulture PlaZa : R. macrophyllum, cv. Snow Lady
- (MCF) Main Courtyard Fountain : cv. Vulcan (check ID)
- (ONE) Overpass North side East : cv. Ramapo, cv. Unique (?); R. impeditum