Rhododendron 'Koster's Brilliant Red' (M)
A deciduous azalea to about 1.5m high, with an upright habit, and elliptic, slightly glossy green leaves that turn red in autumn. Produces clusters of reddish-orange flowers with red spots on the top petals, in late spring. This cultivar was produced in Holland and introduced in 1918; it was initially produced as seedlings repeatedly produced from the same cross, so there is some variation to be found in the descendants that bear this name
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Size
Ultimate height
1–1.5 metresTime to ultimate height
5–10 yearsUltimate spread
1–1.5 metresGrowing conditions
Moisture
Moist but well–drainedpH
AcidColour & scent
Stem | Flower | Foliage | Fruit | |
Spring | Orange Red | Green | ||
---|---|---|---|---|
Summer | Green | |||
Autumn | Green Orange Red | |||
Winter |
Position
- Full sun
- Partial shade
Aspect
North–facing or South–facing or West–facing
Exposure
Sheltered Hardiness
H6Botanical details
- Family
- Ericaceae
- Native to the UK
- No
- Foliage
- Deciduous
- Habit
- Columnar upright
- Potentially harmful
- Harmful if eaten. Wear gloves and other protective equipment when handling. Pets (dogs, cats, rabbits, tortoises) Harmful if eaten - for further information and contact numbers regarding pets, see the HTA guide to potentially harmful plants
- Genus
Rhododendron can be evergreen or deciduous shrubs or trees, with simple leaves, sometimes with a dense colourful indumentum of hairs on the lower side, and funnel-shaped, bell-shaped or tubular flowers that may be solitary or in short racemes
- Name status
Accepted
- Horticultural Group
- Mollis azaleas are deciduous shrubs with unscented, funnel-shaped flowers in a range of colours from white through yellow and orange, to red, opening before the leaves in late spring
How to grow
Cultivation
Grow in moist but well-drained, humus rich, acidic soil, in sun or light shade. Choose a site away from frost pockets and sheltered from strong winds. Mulch annually, ideally with leaf mould. See rhododendron cultivation for more detailed advice
Propagation
Propagate by semi-ripe cuttings in late summer, or by grafting in winter
Suggested planting locations and garden types
- City and courtyard gardens
- Cottage and informal garden
- Patio and container plants
- Flower borders and beds
- Wall side borders
Pruning
Minimal pruning required, may be lightly pruned after flowering; see pruning group 1
Pests
May be susceptible to vine weevil, rhododendron and azalea whitefly, rhododendron leafhopper, Pieris lacebug, scale insects, caterpillars and aphids
Diseases
May be susceptible to powdery mildews, honey fungus, silver leaf and Phytophthora, as well as more specific Rhododendron diseases
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