What hardiness zones is Buddleja davidii suitable for?

Buddleja davidii is butterfly bush (summer lilac), a deciduous shrub growing 5-10 feet (1.5-3 m) tall and 5-10 feet (1.5-3 m) wide. Dense terminal flower panicles 4-12 inches (10-30 cm) in purple, lavender, pink, white, or magenta (varies by cultivar) with orange throats — strongly fragrant. Dark green lanceolate leaves 4-10 inches (10-25 cm), white-felted beneath. Blooms July-October on new (current season's) wood. In Scrophulariaceae. Native to central and western China. Classified as invasive in the Pacific Northwest, parts of the eastern US, the UK, New Zealand, and Australia — self-sows prolifically on disturbed ground, roadsides, and stream banks from thousands of tiny seeds per panicle. This invasive status is the primary limitation — banned from sale in Oregon and Washington. Sterile or low-fertility cultivars reduce but do not eliminate seed production. In zones 5-6 the stems die back to the ground in winter and regrow to full height in one season. Strongly attracts butterflies, bees, and moths. Deer-resistant. Drought-tolerant once established. Non-toxic. Zones 5-9. Full sun. Growth rate is fast.

Native Range

Native to central and western China — Sichuan, Hubei, and adjacent provinces. Found on rocky slopes and disturbed areas. Classified as invasive in multiple countries.

Suggested Uses

Grown in perennial borders (back-of-border) and butterfly gardens spaced 5-10 feet (1.5-3 m). Strongly attracts butterflies. Fragrant. Classified as invasive in several US states and countries — check local regulations; consider sterile cultivars. Deer-resistant. Drought-tolerant. Non-toxic. Zones 5-9.

How to Identify

Identified by dense terminal flower panicles 4-12 inches (10-30 cm) with an orange throat on a large arching shrub with dark green lanceolate leaves white-felted beneath. The dense conical panicle shape, the orange throat, and the white leaf undersides are diagnostic. Distinguished from B. globosa (globe butterfly bush — spherical orange-yellow flower heads) by the elongated panicle shape. In Scrophulariaceae.

Appearance

Size & Dimensions

Height5' - 10'

Width/Spread5' - 10'

Reaches mature size in approximately 3 years

Colors

Flower Colors

Foliage Colors

Fall Foliage Colors

Bloom Information

Bloom Period

~14 weeks

Summer Fall

Summer to fall (July-October). Dense terminal panicles 4-12 inches (10-30 cm) in purple, lavender, pink, white, or magenta with orange throats. 14 weeks of bloom with regular deadheading. Butterfly-, bee-, and moth-pollinated. Thousands of tiny seeds per panicle.

Detailed Descriptions

Flower Description

Purple, lavender, pink, white, or magenta (varies by cultivar) with an orange throat, in dense terminal panicles 4-12 inches (10-30 cm) long

Foliage Description

Dark green above, white-felted beneath (tomentose), lanceolate, 4-10 inches (10-25 cm) long with serrated margins

Growing Conditions

Sun Requirements

Full Sun

Requires 6-10 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

Soil Requirements

pH Range6.0 - 7.5(Neutral)

357912

Soil Types

loam clay sand chalk

Drainagewell drained

Water & Climate

Water Needs

Low

Frost Tolerance

hardy

Time to Maturity

2-3 years

Drought Tolerance

Drought tolerant when established

Care & Maintenance

Care Guide

Full sun (6+ hours). Well-drained soil pH 6.0-7.5. Drought-tolerant once established. Classified as invasive in several US states — check local regulations. Cut back hard to 12-18 inches (30-45 cm) in early spring (March-April) — blooms on new wood. Deadhead spent panicles to extend bloom and reduce seed set. Deer-resistant. Non-toxic. Zones 5-9.

Pruning

Cut back hard to 12-18 inches (30-45 cm) in early spring (March-April) before new growth — blooms on current season's wood. In zones 5-6 the stems die back naturally. Deadhead spent panicles throughout summer to extend bloom and reduce invasive seed production.

Pruning Schedule

early spring

Maintenance Level

moderate

⚠️ Toxicity Warning

Non-toxic