Q: In reading a 1996 “Horticulture” magazine I came across an article listing Scotch broom, Cytisus scoparius, as an invasive/noxious plant. I know it is a problem in California and the Northwest, but I want to make sure it would not be a problem here if I buy one.
A: My colleague Theresa Schrum is a member of the Southeast Exotic Pest Plant Council. She’s seen Scotch broom at Smithgall Arboretum near Gainesville. The entrance to the property is covered in plants which escaped from a nearby location. She’s also seen patches of it along I-85 in Gwinnett County.
I’ve seen the common ornamental maiden grass, Miscanthus sinensis, in wild patches along the highways outside Asheville, NC. It is listed as invasive in Kentucky and Virginia. Theresa advises that it sometimes takes several years for us to notice a problem with a certain plant. Often, this doesn’t happen until we reach a “critical mass” of plants in widespread cultivation. But by that time, it may be too late to shove the genie back in the bottle.
If your heart is set on a yellow-blooming shrub, Theresa recommends the Southern favorite, forsythia, or our native senna, Cassia hebecarpa. You could even try growing our native yellow baptisia, Baptisia sphaerocarpa ‘Screamin’ Yellow’.