Florida Wildflowers: Brown-eyed Susan

Florida Wildflowers: Brown-eyed Susan

Brown-eyed Susan makes a nice addition to a pollinator garden. This one is visited by a scoliid wasp, a parasitoid of soil-inhabiting scarab beetle larvae. Photo credit: Mary Salinas, UF/IFAS Extension.

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. Photo credit: Mary Salinas, UF/IFAS Extension.

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.

Divide Perennials in the Fall

Divide Perennials in the Fall

After a few years, many perennial plants have grown so large that they need to be divided in order to be revived. Overcrowding causes them to bear fewer flowers and, sometimes, to die in the center. Fall is a good time to divide perennials that bloom in spring and summer and are now done blooming for the year. This is a great way also to expand your perennial beds or share some of your perennial favorites with friends and neighbors.

Vibrant blue Stokes' aster. Photo credit: UF/IFAS.

Vibrant blue Stokes’ aster. Photo credit: UF/IFAS.

Some examples of perennials to divide in the fall are:

  • Stokes’ aster, Stokesia laevis
  • Daylily, Hemerocallis spp.
  • Black-eyed Susan, Rudbeckia hirta
  • Yarrow, Achillea millefolium
  • Crocosmia, Crocosmia spp.
  • Flax lily, Dianella tasmanica ‘Variegata’
  • Liriope, Liriope muscari
  • Cast iron plant, Aspidistra elatior

The first step is to dig out the entire clump. If there is enough clearance in the garden bed, start digging about six inches out from the plant and dig straight down beyond the root zone. It’s best to get as much of the roots as possible to lessen the shock of transplanting. If the clump is too heavy to remove, make your divisions right there with a sharp blade, trowel or shovel. Often, you can just pull them apart with your hands.

Before replanting the divisions, consider adding some nutritious compost to those areas of your garden bed to ensure healthy plants. Be sure to replant as soon as feasible to protect the roots from drying out. After replanting, water the transplanted divisions well and mulch appropriately.

To explore further please see:

Gardening with Perennials in Florida

Propagation of Landscape Plants