What hardiness zones is Buddleja davidii suitable for?

Buddleja davidii is suitable for USDA hardiness zones 5, 6, 7, 8, 9.

What are the sun requirements for Buddleja davidii?

Buddleja davidii requires Full Sun.

How much water does Buddleja davidii need?

Buddleja davidii has Low water needs.

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Deciduous Shrubs

Buddleja davidii

butterfly bush

BuddlejaceaeCentral and western China

At a Glance

TypeShrub

HabitMounding

FoliageDeciduous

Height5-10 feet (1.5-3 m)

Width5-10 feet (1.5-3 m)

Maturity3 years

Growing Zones

USDA Hardiness Zones

5 - 9

Zone 5

Zone 6

Zone 7

Zone 8

Zone 9

These zones indicate the coldest temperatures this plant can typically survive.

Frost Tolerancehardy

Key Features

Attracts Pollinators

Attracts Butterflies

Deer Resistant

Drought Tolerant

Fragrant (strong)

Maintenancemoderate

Overview

Buddleja davidii is a fast-growing deciduous shrub native to central China, reaching 5–10 feet (1.5–3 m) tall and 5–10 feet (1.5–3 m) wide in a vigorous, arching mound that dies back partially or to the ground in cold winters and regrows vigorously in spring. It is widely grown for its long, conical flower panicles 6–18 inches (15–45 cm) long, borne from July through October in shades of purple, lavender, pink, white, or magenta, each floret with a small orange throat. The fragrance is honey-sweet and strong. Lance-shaped to elliptic leaves 4–10 inches (10–25 cm) long are dark green above with white-felted undersides. Butterflies and bumblebees visit the flowers heavily; it provides adult nectar but does not support butterfly larval development. Buddleja davidii is listed as a Class B Noxious Weed in Washington State and is on the Oregon noxious weed list, where it self-seeds prolifically along roadsides, stream banks, gravelly slopes, and disturbed areas throughout the PNW — outcompeting native vegetation. Seeds are produced in enormous quantities and dispersed by wind and water. So-called 'sterile' cultivars ('Blue Chip', 'Buzz', 'Miss Molly', 'Miss Ruby') produce significantly fewer seeds than straight species selections but are not fully sterile and should not be planted adjacent to natural areas, waterways, or disturbed ground. If grown, deadheading spent panicles before seed set is essential. The plant is specifically not recommended for planting near stream corridors, roadsides, or restoration sites.

Native Range

Native to central and western China (Hubei, Sichuan, Yunnan provinces) in rocky, disturbed habitats, stream banks, and secondary growth. Introduced to European gardens in the late 19th century; widely naturalized across western North America, Europe, Australia, and New Zealand.

Suggested Uses

Grown as a late-summer pollinator plant and butterfly nectar source in sunny borders. Provides adult butterfly nectar but does not support larval host plant needs. Given its Class B Noxious Weed status in Washington and noxious weed listing in Oregon, planting in gardens adjacent to natural areas, waterways, or disturbed ground is not recommended. If grown, low-fertility cultivars and rigorous deadheading are essential. Many gardeners choose native alternatives — Ceanothus, Penstemon, Agastache, and Symphoricarpos — that provide equivalent or superior pollinator value without invasive risk.

How to Identify

Identified by long conical flower panicles 6–18 inches (15–45 cm) at branch tips covered in small, four-lobed tubular florets with an orange throat — distinctive and unmistakable when in bloom. Lance-shaped to elliptic leaves 4–10 inches (10–25 cm) with serrated margins are dark green above and white-felted beneath; rubbing the leaf underside leaves white fuzz on fingers. The strong honey-sweet fragrance is detectable at a distance. Arching multi-stemmed habit with gray-brown stems. Seed capsules are small, brown, and persistent after bloom.

Appearance

Size & Dimensions

Height5' - 10'

Width/Spread5' - 10'

Reaches mature size in approximately 3 years

Colors

Flower Colors

purple

lavender

pink

white

magenta

Foliage Colors

dark green

Fall Foliage Colors

no change

Bloom Information

Bloom Period

~14 weeks

SummerFall

Blooms July through October, one of the longest flowering seasons of any hardy deciduous shrub. Main flush is July through August; deadheading spent panicles promptly encourages continued flowering into fall. Each panicle lasts 3–5 weeks. Fragrance is strongest on warm sunny days.

Detailed Descriptions

Flower Description

purple, lavender, pink, white, or magenta with orange throat

Foliage Description

dark green above, white-felted beneath

Growing Conditions

Sun Requirements

Full Sun

Requires 6-8 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

loamclaysandchalk

Drainage

well 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

Plant in full sun in well-drained soil; tolerates a wide range of soil types. Drought-tolerant once established. Hard pruning in early spring (March through April, after hard frosts) to 12–18 inches (30–45 cm) from the ground produces the largest, most vigorous flower panicles — the current season's growth bears all flowers. Deadhead spent panicles regularly throughout the season to reduce seed production and prolong bloom; this is especially important given the species' invasive status in the PNW. Do not plant adjacent to waterways, roadsides, natural areas, or disturbed ground where seeds may spread. If planting, select a low-seed-production cultivar and commit to consistent deadheading. Buddleja davidii is a Class B Noxious Weed in Washington; verify current regulations before purchasing.

Pruning

Cut back hard in early spring (March through April) to 12–18 inches (30–45 cm) from the ground — the plant flowers only on new growth, and hard annual pruning produces significantly larger panicles than light pruning. In cold winters, stems may die back further; remove dead wood to the first live buds. Deadhead spent flower panicles throughout the growing season before seeds mature — this is critical for minimizing invasive spread. The plant can be cut to the ground every few years for full renovation.

Pruning Schedule

early spring

Maintenance Level

moderate

⚠️ Toxicity Warning

Non-toxic