Gardening 101: Butterfly Bush

Butterfly Bush, Buddleia 

“Even a quite small garden should have a buddleia,” wrote the late gardening columnist Henry Mitchell, because no plant is better at attracting butterflies. His favorite cultivar was the lavender-flowered ‘Lochinch’, a prolific bloomer discovered in Scotland nearly 80 years ago.

Plant a butterfly bush to help someone smaller and more defenseless than yourself. “If gardeners stopped thinking of insects as enemies, they would find some pleasure in them. Butterflies alone are reason to forget poison sprays,” Mitchell wrote. His suggested planting scheme for a meadow garden to cosset butterflies included (in addition to butterfly bush) cornflowers, poppies, and butterfly weed—which is quite a different plant altogether; Asceplias is a species of milkweed.

But before you turn over the back corner of the garden to this fast-growing, explosive flowering shrub, a note of caution: Butterfly bush is considered invasive in some regions (it is a particularly fast grower in warm climates).

Is butterfly bush the right flowering shrub to plant in your garden? Read on to learn more:

Native to China, butterfly bush is a fast growing deciduous shrub producing long, buttery-sweet blossoms in the summer .  Butterflies behave like kids in a candy store when Buddleia blooms (I have heard our winged friends like the lavender pink-flowered ones the best).

Cold hardy to USDA growing zone 5 and partially evergreen in zone 8 south and warmer regions, some varieties of butterfly bushes can grow as high 12 feet. Other, dwarf varieties top out around 5  feet tall. This bush has major benefits: it grows fast, requires little maintenance, is not attractive to deer, has fragrant flowers, and requires little water. But there is a less attractive aspect to its personality….

Surprising to most people, butterfly bush has been classified as an invasive species in most U.S. regions, crowding out beneficial native plants essential to wildlife. In warm climates, it becomes more of a noxious weed and spreads ferociously through seed dispersal. Luckily, in cooler climates it’s easy to contain if gardeners deadhead the flowers before it sets volunteering seeds.

And despite the “butterfly” name, be aware that this shrub is not a butterfly “host plant” (it doesn’t support butterfly reproduction and lifecycle.)  While butterfly bush does provide copious amounts of nectar to adult butterflies, caterpillars do not feed on this plant.

Given our declining pollinator population, my recommendation is if you already own a butterfly bush, be sure to add native host plants like dill, aster, and milkweed if you want the butterflies to have a complete life cycle in your garden, and use plants that better support your native food web and landscape. “Gardeners who want to support the entire butterfly life cycle and still enjoy brilliant flower clusters should consider native alternatives such as California lilac (Ceanothus), and meadowsweet (Spiraea spp),” writes Justine. Read more in Native Plants: 10 Alternatives to Invasive Garden Invaders.

Cheat Sheet

• Most varieties of butterfly bush are tall and should be placed in the back of garden beds, and because of the summer fragrance sited near patios, porches, window, and places frequented by visitors.
• Buddleia is popular in cottage, deer-resistant, drought-tolerant and pollinator-friendly gardens.
• Butterfly bush flowers come in pink, white, purple, red, and yellow, and make a great cut flower.
• Buddleia looks lovely next to ornamental grasses and salvias.

Keep It Alive

• Planting butterfly bushes in full sun is a must for best flower production and growth habit.
• Butterfly bushes perform best in well-draining soil and are not heavy feeders. Tip: too much fertilitizer encourages leaf growth and not wanted flower production.
• Butterfly bushes are drought tolerant once established. Those grown in pots will need more water.
• Prune spent flower spikes to promote new shoots and flower buds.
• Because they bloom on new wood, in the late winter or early spring prune Buddleia bushes hard to live wood (1 to 2 feet tall) to ensure a compact shape.
• Butterfly bushes are susceptible to capsid bug, caterpillars, weevils, mullein moth, and spider mites. Buds and young leaves can be disfigured and damaged by a moth larva called a budworm.

See more growing tips in Butterfly Bush: A Field Guide to Planting, Care & Design in our curated guides to Shrubs 101. For more reading, see:

• Pollinator Gardens: 8 Easy Steps to Design a Landscape with Native Plants
• Garden Visit: At Home with Winemaker Rosemary Cakebread in St. Helena, CA
• Container Gardening: Sarah Raven’s 7 Tips for Perfect Flower Pots