Rhododendron Rhododendron (PJM Group)
Other Common Name(s):
Other plants called Rhododendron:
- Phonetic Spelling
- roh-do-DEN-dron
- This plant has high severity poison characteristics.
- See below
- Description
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PJM rhododendrons are a group of hybrid, broadleaf evergreen shrubs in the Ericaceae (blueberry) family that were developed by Peter J. Mezitt and his son in the 1930s to be exceptionally winter hardy. The genus name derives from the Greek words rhodo, which means rose, and dendron, meaning tree.
Growing 3 to 6 feet tall and wide, these rhododendrons prefer partial shade and protection from strong winds. They grow well in moist, acidic soils but do not like wet feet. If you have clay soil, amend it with organic material and plant the root ball high in the soil to help with drainage issues. Avoid overwatering and over-fertilizing. Pruning, if desired, may be done after flowering. This plant is resistant to browsing by rabbits.
As with all members of the genus, PJM rhododendrons are perfect as mass plantings in woodland or natural areas and specimens in pollinator gardens. Their green foliage acquires purple tones in winter, making them a wonderful addition to a winter garden. They also make a great informal hedge plant.
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. Full sun can scorch the leaves, and the roots rot if soil does not drain well.
While rhododendrons 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. 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.
- Profile Video:
- See this plant in the following landscape:
- Four-Season Garden
- Cultivars / Varieties:
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- 'Aglo' - pink
- 'Landmark' - near red
- 'Olga' - pink
- 'Pink Diamond'
- 'PJM'
- 'PJM Compact'
- 'PJM Elite'
- 'PJM Elite Star'
- 'PJM Regal'
- 'Aglo' - pink
- 'Aglo' - pink, 'Landmark' - near red, 'Olga' - pink, 'Pink Diamond', 'PJM', 'PJM Compact', 'PJM Elite', 'PJM Elite Star', 'PJM Regal'
- Tags:
- Cultivars / Varieties:
-
- 'Aglo' - pink
- 'Landmark' - near red
- 'Olga' - pink
- 'Pink Diamond'
- 'PJM'
- 'PJM Compact'
- 'PJM Elite'
- 'PJM Elite Star'
- 'PJM Regal'
- 'Aglo' - pink
- 'Aglo' - pink, 'Landmark' - near red, 'Olga' - pink, 'Pink Diamond', 'PJM', 'PJM Compact', 'PJM Elite', 'PJM Elite Star', 'PJM Regal'
- Tags:
-
-
Attributes:
- Genus:
- Rhododendron
- Family:
- Ericaceae
- Life Cycle:
- Woody
- Wildlife Value:
- Tolerates damage by rabbits. Members of the genus Rhododendron support the following specialized bee: Andrena (Andrena) cornelli.
- Dimensions:
- Height: 3 ft. 0 in. - 6 ft. 0 in.
- Width: 3 ft. 0 in. - 7 ft. 0 in.
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Whole Plant Traits:
- Plant Type:
- Poisonous
- Shrub
- Woody Plant Leaf Characteristics:
- Broadleaf Evergreen
- Habit/Form:
- Rounded
- Growth Rate:
- Medium
- Maintenance:
- Medium
- Texture:
- Coarse
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Cultural Conditions:
- Light:
- Partial Shade (Direct sunlight only part of the day, 2-6 hours)
- Soil Texture:
- High Organic Matter
- Loam (Silt)
- Soil pH:
- Acid (<6.0)
- Soil Drainage:
- Good Drainage
- Available Space To Plant:
- 3 feet-6 feet
- NC Region:
- Coastal
- Mountains
- Piedmont
- USDA Plant Hardiness Zone:
- 4a, 4b, 5b, 5a, 6a, 6b, 7a, 7b, 8b, 8a
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Fruit:
- Fruit Type:
- Capsule
-
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Flowers:
- Flower Color:
- Pink
- Purple/Lavender
- Flower Inflorescence:
- Raceme
- Flower Value To Gardener:
- Showy
- Flower Bloom Time:
- Spring
- Flower Shape:
- Funnel
- Flower Petals:
- 4-5 petals/rays
- Flower Description:
- Showy clusters of lavender, pink or rose flowers
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Leaves:
- Woody Plant Leaf Characteristics:
- Broadleaf Evergreen
- Leaf Color:
- Green
- Leaf Feel:
- Leathery
- Deciduous Leaf Fall Color:
- Purple/Lavender
- Leaf Arrangement:
- Alternate
- Leaf Shape:
- Elliptical
- Leaf Margin:
- Entire
- Hairs Present:
- No
- Leaf Length:
- 1-3 inches
- Leaf Description:
- Elliptic, hairless, leathery, dark green leaves (to 2.5” long); foliage acquires purple tones in winter.
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Stem:
- Stem Is Aromatic:
- No
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Landscape:
- Landscape Location:
- Naturalized Area
- Woodland
- Landscape Theme:
- Pollinator Garden
- Winter Garden
- Design Feature:
- Hedge
- Mass Planting
- Specimen
- Attracts:
- Specialized Bees
- Resistance To Challenges:
- Rabbits
- Problems:
- Poisonous to Humans
- Problem for Cats
- Problem for Dogs
- Problem for Horses
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-
Poisonous to Humans:
- Poison Severity:
- High
- Poison Symptoms:
- Salivation, watering of eyes and nose, abdominal pain, loss of energy, depression, nausea and vomiting, diarrhea, weakness, difficult breathing, progressive paralysis of arms and legs, cardiac failure, coma.
- Poison Toxic Principle:
- Andromedotoxin, Grayantoxin
- Causes Contact Dermatitis:
- No
- Poison Part:
- Bark
- Flowers
- Fruits
- Leaves
- Roots
- Sap/Juice
- Seeds
- Stems
