Rhododendron impeditum
dwarf purple rhododendron
Western China — Yunnan and Sichuan provinces; alpine meadows and rocky slopes at 10,000-14,000 feet (3,000-4,300 m)
Overview
Rhododendron impeditum is dwarf purple rhododendron (cloudland rhododendron), a tiny dense mounding evergreen shrub growing 12-18 inches (30-45 cm) tall and 18-24 inches (45-60 cm) wide. Violet-blue to purplish-blue funnel-shaped flowers 0.5-0.75 inch (1.3-2 cm) in clusters of 2-4 in April-May (3 weeks). Tiny dark green scaly (lepidote) aromatic leaves 0.3-0.5 inch (8-13 mm) densely interlocking into a cushion-like form; purple-bronze winter tones. In Ericaceae spp.. Impeditum = tangled (the interlocking branches). An alpine species from Yunnan and Sichuan at 10,000-14,000 feet (3,000-4,300 m). Among the smallest rhododendrons. Extremely slow-growing (10-15 years to mature) — this is the primary limitation. Cold-hardy (zone 4). Requires strongly acidic soil (pH 4.5-5.5). Contains grayanotoxin — all parts toxic. Not drought-tolerant. Not deer-resistant. Parent of many dwarf hybrids. Zones 4-8. Part shade. Growth rate is very slow.
Native Range
Native to western China — Yunnan and Sichuan provinces. Found on alpine meadows and rocky slopes at 10,000-14,000 feet (3,000-4,300 m).Suggested Uses
Grown in rock gardens, alpine beds, trough gardens, and in containers of at least 3 gallons (11 L) with strongly acidic mix, spaced 18-24 inches (45-60 cm). Tiny alpine rhododendron. Very slow. All parts toxic. Zones 4-8.How to Identify
Appearance
Size & Dimensions
Height1' - 1'6"
Width/Spread1'6" - 2'
Reaches mature size in approximately 15 years
Bloom Information
Mid spring (April-May). Violet-blue to purplish-blue funnel-shaped flowers 0.5-0.75 inch (1.3-2 cm) in clusters of 2-4 at branch tips. 3 weeks. Bee-visited.
Detailed Descriptions
Flower Description
Violet-blue to purplish-blue, funnel-shaped, 0.5-0.75 inch (1.3-2 cm), in clusters of 2-4 at branch tips; April-May; the flowers are large relative to the plant sizeFoliage Description
Dark green, tiny, elliptic, 0.3-0.5 inch (8-13 mm), densely scaly (lepidote) beneath, aromatic when crushed; purple-bronze winter tones; the tiny interlocking leaves create a dense cushion-like textureGrowing Conditions
Sun Requirements
Requires 3-6 hours of direct sunlight daily
• Full Sun: 6+ hours of direct sunlight
• Partial Shade: 3-6 hours of direct sunlight
• Full Shade: Less than 3 hours of direct sunlight
Care & Maintenance
Care Guide
Part shade (3-6 hours). Well-drained strongly acidic soil pH 4.5-5.5. Not drought-tolerant. Extremely slow-growing (10-15 years). Cold-hardy (zone 4). Contains grayanotoxin — all parts toxic. Not deer-resistant. Zones 4-8.Pruning
Minimal pruning needed. The natural dense cushion form is self-maintaining. Remove any dead or damaged growth in late spring (May-June).Pruning Schedule
J
F
M
A
M
J
J
A
S
O
N
D
late spring
Container Growing
✓ Suitable for container growing
Minimum container size: 3 gallons