Buddleia Purple Emperor
Purple Emperor Butterfly Bush
Buddleja davidii ‘Purple Emperor’ — commonly known as Purple Emperor Butterfly Bush — is a vigorous deciduous shrub valued for its deep royal-purple flower panicles, strong fragrance, and long bloom season. Blooming from mid-summer through fall, it provides bold color and exceptional pollinator activity, especially in larger landscape settings.
Key features
Width / spread: 6–8 ft (arching habit may appear slightly wider with age)
Height: 8–10 ft (can be maintained at 6–8 ft with annual pruning)
Flower color: Deep royal purple with orange eye
Bloom time: Mid-summer through fall
Foliage: Gray-green, lance-shaped leaves
Form: Upright, arching shrub
Life cycle: Deciduous shrub
Growing conditions
Sun: Full sun (required for best flowering and color saturation)
Soil: Well-drained; average to lean soils preferred
Water: Low to moderate; drought tolerant once established
Hardiness:
Zone Low: 5b
Zone High: 9a
Landscape use
Specimen shrub
Back of shrub borders and perennial gardens
Butterfly and pollinator gardens
Informal hedges and screens
Large landscape plantings
Notes
Produces long, richly colored purple panicles with strong fragrance
Blooms on new wood — prune hard in early spring to control size and maximize flowering
Highly attractive to butterflies, bees, and hummingbirds
Fertile cultivar — may self-seed; restricted or discouraged in some regions
- Plant type
- Deciduous Shrub, Flowering Shrub
- Height
- 5-6'
- Width
- 4-5'
- Hardiness zones
- 6–8
- Sunlight
- Full Sun
- Growth rate
- Fast
- Bloom time
- Early Fall, Fall, Late Summer, Summer
- Leaf color
- Green
- Fall color
- Green
- Attracts
- Butterflies
- Soil
- Loamy
- Landscape use
- Foundation
- Shape
- Mounded
- Bark
- Exfoliating
- Fruit
- Yes
- Fragrant
- Yes
- Deer resistant
- Yes
- Salt tolerant
- Yes
- Drought tolerant
- No
