Rhododendron Thunder
Thunder (Rhododendron ‘Thunder’) is an evergreen rhododendron with purple flowers. Its display arrives in the early-to-middle part of the rhododendron flowering season, with the exact timing influenced by local weather. Individual flowers measure about 1½ inches across. The flower tubes widen into flared faces that display the color clearly. Wavy petal edges give the clusters additional texture. Clusters commonly carry about 3-5 blossoms.
The plant develops a dense crown. Its foliage is retained through winter, keeping a leafy framework between flowering seasons. Cool-season foliage can develop burgundy tones. It can provide a flowering focal point within a mixed shrub border or woodland-edge planting.
Give it acidic, humus-rich soil that stays moist and drains freely. A sheltered position with filtered light or morning sun is a useful starting point; protect the roots from prolonged drying and keep mulch clear of the stems.
Size guide
• Height: About 3 ft at 10 years; growth continues afterward
• Width: Allow for the cultivar’s natural branch spread; a verified numerical spread is not available in this reference.
Hardiness
• Approximate cold tolerance: -20°F
• USDA cold-limit equivalent: Zone 5a
This equivalence is calculated from the published temperature rating. Local conditions and summer climate also affect performance.
Best Uses
• Border
• Woodland Gardens
• Accent Plant
- Plant type
- Broadleaf Evergreen, Evergreen Shrub, Flowering evergreen shrub
- Height
- 3 ft+
- Width
- 4'-6'
- Hardiness zones
- 5a–7
- Sunlight
- Part shade
- Bloom time
- Spring to summer
- Flower color
- Purple
- Leaf color
- Green
- Fall color
- Burgundy
- Attracts
- Butterflies
- Soil
- Acidic, Humus rich, Moist well-drained
- Landscape use
- Accent Plant, Border, Woodland Gardens
- Shape
- Dense
- Fruit
- No
- Fragrant
- No
- Deer resistant
- No
- Salt tolerant
- No
- Drought tolerant
- No
- 10-year height
- 3 ft