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Rhododendron 'Mary Helen' (Glenn Dale) (EA)

azalea 'Mary Helen'

A spreading evergreen shrub with glossy green, small leaves and large, white flowers with a wavy margin up to 5cm across with a yellow spotting and dark anthers, produced in early June.

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Size
Ultimate height
0.5–1 metres
Time to ultimate height
5–10 years
Ultimate spread
1–1.5 metres
Growing conditions
Clay
Loam
Sand
Moisture
Moist but well–drained
pH
Acid
Colour & scent
StemFlowerFoliageFruit
Spring White Yellow Green
Summer Green
Autumn Green
Winter
Position
  • Partial shade
Aspect

East–facing or North–facing or South–facing or West–facing

Exposure
Sheltered
Hardiness
H5
Botanical details
Family
Ericaceae
Native to the UK
No
Foliage
Evergreen
Habit
Spreading branched
Potentially harmful
Harmful if eaten. Wear gloves and other protective equipment when handling
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
Evergreen azaleas are compact evergreen shrubs with small leaves and terminal racemes of small, funnel-shaped, usually unscented flowers in early summer

How to grow

Cultivation

Grow in moist but well-drained, humus rich acid soil in a sheltered position in part shade; see rhododendron cultivation

Propagation

Propagate by semi-ripe cuttings in late summer

Suggested planting locations and garden types
  • City and courtyard gardens
  • Cottage and informal garden
  • Patio and container plants
  • Low Maintenance
Pruning

Pruning group 8

Pests

May be susceptible to vine weevil, rhododendron leafhopper, pieris lacebug, scale insects, caterpillars and aphids

Diseases

May be susceptible to various Rhododendron diseases including powdery mildew, rhododendron petal blight, rhododendron bud blast, silver leaf and honey fungus

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