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Photo Credit: Kingsbrae Garden, Flickr -
Photo Credit: Forest and Kim Starr, Starr Environmental, Bugwood.org -
Photo Credit: Forest and Kim Starr, Starr Environmental, Bugwood.org -
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Photo Credit: John Ruter, University of Georgia, Bugwood.org
Also known as: orange-eye butterfly bush, summer lilac
You can’t blame gardeners for adoring butterfly bush. The shrub’s purple-and-orange flowers are as dazzling to the human eye as they are to pollinators. Unfortunately, this attractive plant does not always stay where we plant it. When it escapes into natural areas, it can become extremely invasive, choking out native plants and damaging ecosystems.
Description:
| Life Cycle: | Perennial (life cycle lasts more than one year) |
| Early Detection and Rapid Response species: | No |
| Height: | 10 – 15 feet tall (3 – 5 meters) |
| Leaf Description: | Leaves are arranged opposite along the stem and spear shaped. Each leaf is gray-green with wooly, white hairs underneath. |
| Fruit & Flower Description: | Produces small, fragrant flowers arranged in a cone-shaped flower spike. Flowers have 4 petals and are commonly bright purple, other varieties may be white, pink, or red, but all have orange centers. |
| Bloom Time: | July to September |
Habitat:
Takes over bare or disturbed sites, including roadsides, riparian areasAreas that are directly adjacent to flowing streams, creeks, or rivers., pastures, urban areas, and wetlands. Some of the worst infestations are along riverbanks and in burned areas where reforestation is underway.
Impact:
- Spreads by seed – up to 3 million per plant – which are viable in soils for 3 to 5 years.
- It forms dense thickets, especially along riverbanks and gravel bars, altering soil nutrients and crowding out native trees and shrubs.
What you can do about it:
- The biggest challenge for controlling butterfly bush is its popularity – in addition to naturally spreading, it is also spreading because people are purchasing and planting it. There are many native alternatives available to plant instead of butterfly bush, Native Plants for Willamette Valley provides several options for local gardeners.
- If you have butterfly bush in your garden, make sure it doesn’t go to seed. Cut off fading flowers before they produce seeds, place them in a plastic bag, and throw them away in the trash— not your yard waste bin or home compost.
Look-alikes:
Butterfly bush looks similar to the Pacific Northwest native Douglas spirea (Spiraea douglasii). Douglas spirea has similar cone-shaped flower spikes but are usually pink rather than purple. Both plants blooms at a similar time, July through September.
Noxious Weed Listing:
| State of Oregon: | Class B |
| State of Washington: | Class B |
More Resources:
- Pacific Northwest Weed Management Handbook: Butterflybush
- University of California, Weed Research & Information Center: Butterflybush