Rhododendron mucronulatum
Korean Rhododendron
Ericaceae
ExpandHabitat
- 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.