Black-eyed Susan, Rudbeckia hirta, has been a very popular garden perennial for generations. Fewer gardeners have experience with, or even heard of its’ close relative, brown-eyed Susan, Rudbeckia triloba. So, what is the difference between them?
- Brown-eyed Susan has more numerous flowers and generally flowers for a longer period in spring, summer, and fall.
- Black-eyed Susan has bigger flowers and bigger leaves.
- Both species are perennial, but the brown-eyed Susan tends to die out sooner after a few years. The good news is that both readily spread through seed to replace older plants.
Brown-eyed Susan is native to the eastern and central United States and, although native to Florida, it has only been vouchered in the wild in 5 counties in Florida. Gardeners can find seed and plants readily online and at a few native plant nurseries. It is best to try to source wildflower seed from plants grown in the same region. Brown-eyed Susan seed from plants grown in Nebraska or Michigan may not be as well adapted to the Florida environment as locally grown seed.
If you want to add this pollinator attracting perennial to your garden, choose a spot that is sunny or partly sunny. Although it prefers moist soil, brown eyed Susan adapts to most soil types and is drought tolerant after establishment.