Korean Rhododendron seeds

Habitat

native to northern China, Korea, Japan
zone 4
Habit and Form

a deciduous shrub
4′ to 8′ tall
develops an upright, rounded or oval habit

Summer Foliage

1″ to 4″ long, 0.5″ to 1″ wide
elliptical to somewhat lanceolate
alternate leaf arrangement
aromatic when leaves are bruised/crushed
medium-green foliage color

Autumn Foliage

mix of yellow, orange and wine
colors later than many plants

Flowers

blooms in early April
light rosy purple
each flower with a 1.5″ diameter
borne in clusters of 3 to 6
showy in bloom

Fruit

a small, dehiscent capsule
not ornamentally attractive
Bark

light brown and smooth
not a major ornamental characteristic
Culture

full sun to light shade
prefers moist, cool, acidic, well-drained, organic soil
situate it where it remains cool in the spring to delay bloom a bit
Landscape Use

foundation plants
naturalistic areas
shrub borders
groupings and mass plantings
useful for early spring color
mixes well with evergreens
Liabilities

comes into bloom during the first warm spring weather making it subject to flower injury from frosts
phytophthora root rot on wet, heavy soils
chlorosis on high pH soils
borer occasionally
ID Features

leaves are deciduous
twigs with yellow, resin-like dots
flower buds clustered at twig tips
early period of bloom
late yellow-orange-red fall color
Propagation

by seed
cultivars by cuttings or tissue culture
Cultivars/Varieties

While many cultivars are listed, few besides ‘Cornell Pink’ are commonly available.

‘Album’ – This plant offers white flowers with just a tinge of pink.

‘Cornell Pink’- The most common form and a very popular plant, this cultivar features clear pink flowers with no blue tones. It grows slowly and performs reliably. Plants sold as ‘Storrs Pink’ appear very similar, if not the same.

‘Crater’s Edge’ (also listed as ‘Crater Edge’) – This is a dwarf form that grows to only 3′ tall with lavender-pink flowers that open from reddish buds. ‘Nana’ is a 2′ dwarf form with purple blooms and reddish fall color.