Ask Mr. Smarty Plants

Common swales are typically vegetated with turf grass and are a conveyance tool, basically a grassy stormwater sewer that conveys water as quickly as possible from Point A to Point B. A bioswale differs in that the turf grass is replaced with native prairie vegetation. This will significantly reduce the flow velocity (slow down of the runoff) in the swale’s drainage course. The residence time of the runoff is thus increased, which gives it the time to be stored, filtered, and infiltrated. These processes remove pollutants and suspended solids from runoff.

We found this information on bioswale construction from the USDA, which shows compost tilled into the native soil (clay, in this instance) to facilitate the drainage. The plants we have selected are all perennial, and will grow in moist soils, but can tolerate some drought. These are plants with fibrous roots that will hold in the soil when water is rushing by, help to slow it down, and permit the pollutants in the water to be filtered out. Follow each link to the page on that individual grass to determine how much sun it needs and what soils it does best in. We have checked to make sure each grass is native in and around Volusia County, so the soils are probably all compatible.

Since our suggestions are basically for prairie grasses, you might be interested in reading our How-To Article Recreating a Prairie, which has instructions for time of year to be planting, preparing the soil, planting and caring for the grasses. When you are ready to begin, go to our Native Plant Suppliers section, put your town and state in the "Enter Search Location" box, and you will get a list of native plant nurseries, seed companies and landscape consultants in your general area who can help you select the right plants for your purpose.

Native grasses for a bioswale in Florida:

Andropogon glomeratus (bushy bluestem)

Andropogon virginicus (broomsedge bluestem)

Muhlenbergia capillaris (hairawn muhly)

Paspalum floridanum (Florida paspalum)

Panicum virgatum (switchgrass)

Rhynchospora latifolia (sandswamp whitetop)

Schoenoplectus tabernaemontani (softstem bulrush)

Tripsacum dactyloides (eastern gamagrass)

From our Native Plant Image Gallery:

Andropogon glomeratus

Andropogon virginicus

Muhlenbergia capillaris

Paspalum floridanum

Panicum virgatum

Rhynchospora latifolia

Schoenoplectus tabernaemontani

Tripsacum dactyloides