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Dr. A. Blok Rhododendron

Rhododendron (roh-do-DEN-dron)

Family: Ericaceae Unknown Shrub (3-15 ft)

'Dr. A. Blok' rhododendron is a compact, evergreen shrub in the Ericaceae (blueberry) family that typically grows to a maximum height and width of 7 feet. The genus name derives from the Greek words rhodo, which means rose, and dendron, meaning tree. Plant this cultivar in a location with partial or light shade and organically rich, acidic soils that drain well. It will not tolerate dense clay. This shrub will require regular watering, and the roots may rot if the soil does not drain well. Plant the root ball high in the soil to help with drainage. Avoid overwatering and over-fertilizing. Prune rhododendrons and azaleas after they bloom to preserve the current season's bloom, and allow time for the plant to produce flower buds for next year's bloom. Rhododendrons and azaleas set next year's flower buds by mid to late summer. This plant makes a great addition to a shady border, as a low hedge, or an accent plant. Use it as an understory shrub in a woodland garden or naturalized area, or in a pollinator garden where its showy, bright pink flowers will attract bees. Insects, Diseases, and Other Plant Problems: Insect problems include aphids, borers, lace bugs, leafhoppers, mealybugs, mites, nematodes, scale, thrips, and whitefly. Diseases include canker, crown rot, root rot, leaf spot, rust, and powdery mildew. This plant is frequently damaged by deer. While these shrubs remain very popular for landscape use, many cultivars are susceptible to Phytophthora root rot– this leads to leaf loss, reduced vigor, branch dieback, and wilting. Implement good cultural practices first, such as improving drainage with organic matter or berms and avoiding overwatering or overfertilization. However, if you have a site with a history of this disease, consider planting one of the root rot-resistant alternative species listed in the left-hand sidebar. For suitable alternatives, see this video created by Charlotte Glen as part of the Plants, Pests, and Pathogens series. VIDEO Created by Elizabeth Meyer for " Trees, Shrubs and Conifers " a plant identification course offered in partnership with Longwood Gardens. More information on Rhododendron .

Source: NC State Extension Gardener Plant Toolbox ↗ NC State Extension Gardener Plant Toolbox, 55 attributes.

How it fits the guild

Guild layer 3 - Shrub (3-15 ft) Optimal soil pH Acid (<6.0)
See companions & conflicts ↓

Companions & Conflicts

Curated pairwise relationships between this plant and others in the library — who feeds whom, who competes, who confuses the pests. Green reads as a good pairing, red as one to avoid.

No curated interactions recorded for this species yet.

Also noted by NC State

Related species the NC State Plant Toolbox flags for this plant — look-alikes to tell apart, and plants that play a similar role in a planting. Ones we carry in the library are linked.

Fills a similar niche Rhododendron minus var. chapmanii Rhododendron x hybridum Glenn Dale Group Rhododendron yakushimanum
Similar, less problematic Camellia sasanqua Ilex cornuta

Full plant profile

Growing Conditions
Plant type
Poisonous; Shrub
Life cycle
Woody
USDA zones
6a, 6b, 7a, 7b, 8a, 8b
Light
Dappled Sunlight (Shade through upper canopy all day)
Soil texture
High Organic Matter
Soil pH
Acid (<6.0)
Soil drainage
Good Drainage | Moist
Available space
3 feet-6 feet; 6-feet-12 feet
NC region
Coastal; Mountains; Piedmont
Mature size
Height: 4 ft. 0 in. - 9 ft. 0 in. | Width: 4 ft. 0 in. - 7 ft. 0 in.
Growth rate
Medium
Maintenance
Low
Canopy layer
3 - Shrub (3-15 ft)
Form & Appearance
Habit / form
Rounded
Foliage
Broadleaf Evergreen
Leaf color
Green
Leaf type
Simple
Leaf arrangement
Alternate
Leaf shape
Elliptical
Leaf margin
Entire
Leaf feel
Leathery
Leaf size
3-6 inches long, 1-3 inches wide
Hairs present
No
Leaf detail
Dark green leathery foliage.
Flower color
Pink
Flower form
Raceme
Flower shape
Funnel
Flower detail
Hot pink flowers appear mid to late spring.
Bloom time
Spring
Fruit type
Capsule
Wildlife & Ecology
Native status
Unknown
Wildlife value
Members of the genus Rhododendron support the following specialized bee: Andrena (Andrena) cornelli. Deer browse this plant.
Attracts
Specialized Bees
Food & Medicine
Harvest time
Fall
Fruit type
Capsule
Landscape Use
Landscape location
Naturalized Area; Woodland
Design feature
Accent; Border; Hedge
Garden tags
#evergreen #spring flowers #pink flowers #spring interest #problem for cats #problem for dogs #problem for horses #shrub #partial shade tolerant #acidic soils tolerant #flowers late spring #understory shrub #showy flowers #naturalized area #flowers mid-spring #low hedge #pollinator plant #evergreen shrub #border planting #low maintenance #deer browsing plant #specialized bees #bee friendly #poisonous #hedge #woodland #accent #shrub border #compact
Problems & Resistance
Insect problems
Rhododendron Gall Midge; Rhododendron Borer; Arthropod Pests of Rhododendron; Rhododendron Pest Management Calendar; Rhododendron Lace Bug; Pests of Rhododendron
Problems
Poisonous to Humans; Problem for Cats; Problem for Dogs; Problem for Horses
Poison severity
Low
Poison parts
Bark; Flowers; Fruits; Leaves; Sap/Juice; Stems
Poison symptoms
While the plants are known to contain toxins, ingestion of moderate amounts of azalea (nectar or leaves) poses little toxic hazard.
Toxic principle
Grayanotoxins
Contact dermatitis
No
Toxicity summary
Low severity poison; parts: Bark; Flowers; Fruits; Leaves; Sap/Juice; Stems

Planted at Hunnicutt

Nobody’s planted this one yet.