Rhododendron 'Treasure' (Treasure Rhododendron)


Michael's Opinion

This evergreen specimen is an interesting upright shrub, the dark green foliage contrasts with the showy clusters of flowers making it stand out in the garden in spring. Resistant to deer and rabbits making it perfect for woodland gardens and mass planting.

Botanical Information

FamilyEricaceae
GenusRhododendron
Cultivar'Treasure'
CategoryWoody
TypeShrub (evergreen)
ReferencesReiley, H. (2004). Success With Rhododendrons and Azaleas (Rev. ed.). Portland: Timber Press. Cullen, J., & Garden, E. (2005). Hardy Rhododendron Species: A Guide to iIdentification. Portland, Or.: Timber Press.
Ethnobotanical Uses
Disclaimer
Rhododendron 'Treasure' is grown for its attractive flowers and evergreen foliage. Use for mass or group plantings or as a specimen plant.

Details

USDA Hardiness Zone6 - 8
USDA Hardiness Ref.
Canadian Hardiness Zone5a - 8a
Canada Hardiness Ref.
RHS Hardiness ZoneH4 - H7
RHS Hardiness Ref.
Temperature (°C)-23 -(-7)
Temperature (°F)-10 - 20
Height1 - 2 m
Spread1 - 2 m
GrowthMedium
Flowering PeriodApril, May

Description and Growing Information

General DescriptionA medium sized shrub with dark green evergreen foliage. Clusters of pink flowers contrast against the foliage during spring.
ID CharacteristicAn upright spreading shrub. Leaves are whorled, smooth and oval shaped. The bark is smooth and can range from chocolate-brown to grey.
ShapeA vigorous spreading plant, becoming an upright shrub over time.
LandscapeAn excellent addition to winter landscapes, woodland margins, foundation plantings, shade gardens, mixed borders, mass planting, and shrub borders.
PropagationGrafting and layering, take short cuttings of mature new growth. Place in well drained moist soil, keep in high humidity and indirect light.
CultivationBest grown in well drained acidic soil with the pH range of 4-6 and partial sun; mulch will assist greatly in retaining moisture so roots will not dry out.
PestsSusceptible to many pests such as aphids, caterpillars, nematodes, scale, lace bugs, mealy bugs, borers, and white fly. Diseases include crown rot, leaf gall, rust, powdery mildew, blights, root rot, and leaf spot. Resistant to deer and rabbits.
HabitatHorticultural origin.
Bark/Stem DescriptionSmooth bark that starts out chocolate-brown during new growth gradually turning grey as it matures.
Flower/Leaf Bud DescriptionFlower buds are large, glabrous green and underlined by white, pink, and light red. Cold winters may cause freezing and damage the buds, potentially reducing flower production.
Leaf DescriptionDark green, medium sized oval shaped leaves. This dense spreading foliage maintains the same dark green colour year round.
Flower Description1-4 per cluster, flowers bloom in April-May in white, pink, and light red.
Colour DescriptionFoliage dark green, brownish-grey bark with white, pink and pale red flowers.
Texture DescriptionA medium-coarse textured plant.

Photographs