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Impeditum Rhododendron Rhododendron impeditum

Previously known as:

  • Rhododendron impeditum 'Impeditum'
Phonetic Spelling
roh-do-DEN-dron im-ped-EYE-tum
This plant has high severity poison characteristics.
See below
Description

Dwarf purple rhododendron is a woody, compact, slow-growing, broadleaf evergreen shrub or groundcover in the Ericaceae (blueberry) family. It is native to China. This rhododendron grows to a height of 1 foot and width of 1 to 2 feet. The genus name derives from the Greek words rhodo, which means rose, and dendron, meaning tree.

This plant prefers moist, well-drained, acidic soil in dappled shade and protection from afternoon sun which can scorch the leaves. It does not tolerate dense clay, so if you have clay soil, amend with organic material. The roots may rot if soil does not drain well. Plant the root ball high in the soil to help with drainage issues. Avoid overwatering and over-fertilizing.  

Dwarf purple rhododendron blooms in the spring with spectacular purple flowers that completely cover the plant. It has fragrant, tiny, leathery, gray-green leaves that provide year-round interest. 

Plant it in small groups in border fronts, rock, or woodland gardens. Plant it at about 15 inches apart and the plants will grow together to form a dense groundcover. This plant is often chosen for bonsai. It is resistant to damage by deer.

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. 

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.  

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.

More information on Rhododendron.

Profile Video:
See this plant in the following landscape:
Cultivars / Varieties:
  • 'Tiny Cloud'
'Tiny Cloud'
Tags:
#showy flowers#small spaces#easy to grow#purple flowers#slow growing#fragrant leaves#bonsai#spring flowers#winter interest#dwarf#cottage garden#mass planting#year-round interest#specialized bees#edging#deer resistant#rock garden#border planting#courtyard garden#leathery leaves#Asian garden#flowers late spring#gray-green leaves#border front#small group plantings#compact habit#problem for cats#problem for dogs#bee friendly#problem for horses#tiny leaves#container plant#flowers midspring#patio#woodland
 
Cultivars / Varieties:
  • 'Tiny Cloud'
'Tiny Cloud'
Tags:
#showy flowers#small spaces#easy to grow#purple flowers#slow growing#fragrant leaves#bonsai#spring flowers#winter interest#dwarf#cottage garden#mass planting#year-round interest#specialized bees#edging#deer resistant#rock garden#border planting#courtyard garden#leathery leaves#Asian garden#flowers late spring#gray-green leaves#border front#small group plantings#compact habit#problem for cats#problem for dogs#bee friendly#problem for horses#tiny leaves#container plant#flowers midspring#patio#woodland
  • Attributes:
    Genus:
    Rhododendron
    Species:
    impeditum
    Family:
    Ericaceae
    Life Cycle:
    Woody
    Recommended Propagation Strategy:
    Grafting
    Layering
    Seed
    Country Or Region Of Origin:
    China
    Wildlife Value:
    Members of the genus Rhododendron support the following specialized bee: Andrena (Andrena) cornelli.
    Dimensions:
    Height: 1 ft. 0 in. - 1 ft. 0 in.
    Width: 1 ft. 0 in. - 2 ft. 0 in.
  • Whole Plant Traits:
    Plant Type:
    Ground Cover
    Poisonous
    Shrub
    Woody Plant Leaf Characteristics:
    Broadleaf Evergreen
    Habit/Form:
    Dense
    Mounding
    Growth Rate:
    Slow
    Maintenance:
    Low
  • Cultural Conditions:
    Light:
    Full sun (6 or more hours of direct sunlight a day)
    Partial Shade (Direct sunlight only part of the day, 2-6 hours)
    Soil Texture:
    High Organic Matter
    Soil pH:
    Acid (<6.0)
    Soil Drainage:
    Good Drainage
    Available Space To Plant:
    Less than 12 inches
    12 inches-3 feet
    NC Region:
    Coastal
    Piedmont
    USDA Plant Hardiness Zone:
    4a, 4b, 5a, 5b, 6a, 6b, 7a, 7b, 8a, 8b
  • Fruit:
    Fruit Color:
    Brown/Copper
    Display/Harvest Time:
    Fall
    Fruit Type:
    Capsule
  • Flowers:
    Flower Color:
    Blue
    Purple/Lavender
    Flower Inflorescence:
    Raceme
    Flower Value To Gardener:
    Showy
    Flower Bloom Time:
    Spring
    Flower Shape:
    Funnel
    Flower Petals:
    4-5 petals/rays
    Flower Size:
    1-3 inches
    Flower Description:
    1" blue-purple flowers completely cover the shrub in the mid to late spring
  • Leaves:
    Woody Plant Leaf Characteristics:
    Broadleaf Evergreen
    Leaf Color:
    Gray/Silver
    Green
    Leaf Feel:
    Leathery
    Leaf Value To Gardener:
    Fragrant
    Leaf Type:
    Simple
    Leaf Shape:
    Ovate
    Leaf Margin:
    Entire
    Hairs Present:
    No
    Leaf Length:
    < 1 inch
    Leaf Width:
    < 1 inch
    Leaf Description:
    Fragrant, simple leathery gray-green leaves withe entire margins.
  • Stem:
    Stem Is Aromatic:
    No
  • Landscape:
    Landscape Location:
    Container
    Patio
    Woodland
    Landscape Theme:
    Asian Garden
    Rock Garden
    Design Feature:
    Border
    Mass Planting
    Small groups
    Attracts:
    Specialized Bees
    Resistance To Challenges:
    Deer
    Problems:
    Poisonous to Humans
    Problem for Cats
    Problem for Dogs
    Problem for Horses
  • 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