Description:
Butterfly bush (Buddleja davidii), an ornamental native to China, is an invasive species in Oregon and many other areas. In Oregon, butterfly bush invades disturbed areas, particularly riparian areas. The Oregon nursery industry has the highest farm-gate value of all agricultural commodities and butterfly bush is a significant plant to them. However, the nursery industry does not appear to be a major source of invasion because of their pruning production practices. Butterfly bush is a unique plant because it does not release its seed until mid to late winter. The dispersal mechanisms of butterfly bush are not well documented, but wind is one possibility. Formulations of glyphosate effectively control butterfly bushes up to two years old. Both spraying a dilute herbicide on the entire plant and painting herbicide concentrate on recently cut stumps are effective in controlling butterfly bush, but stump painting may be the preferred option in natural areas that butterfly bush invades.