Native Plants for Kentucky

Central Kentucky's Inner Bluegrass sits on limestone unusually rich in phosphorus. The soils derived from it are deep, fertile, and near neutral, and they are the reason the region became horse country: the mineral content builds bone in grazing animals.

For plants, the same chemistry means a calcium-loving flora quite different from the acid-soil communities that dominate much of the eastern United States. The original vegetation here was not closed forest but savanna-woodland, open groves of bur oak, blue ash, and chinquapin oak over a grassy ground layer, kept open by grazing bison and elk and by fire. Almost none of it survives, and the ancient open-grown trees standing in Bluegrass pastures are its last remnants.

The rest of the state

Kentucky is not all Bluegrass. The Cumberland Plateau in the east is sandstone, acidic, steep, and forested, with a flora closer to West Virginia's. The Pennyroyal region in the south-central runs on limestone again, riddled with karst: sinkholes, caves, and disappearing streams, including the longest cave system known anywhere.

The Jackson Purchase in the far west is coastal plain, flat and sandy, with bottomland forest along the rivers. Between these, the Knobs form a ring of steep conical hills around the Bluegrass.

Karst and drainage

In karst country, water behaves unusually. Rain disappears into sinkholes rather than running off in streams, soil over the rock can be thin, and sites dry quickly after storms. Sinkhole bottoms, on the other hand, collect water and cold air and grow a moisture-loving flora.

Read the microsite before planting. In this state a low spot and a high spot fifty feet apart can call for entirely different species.

Practical choices

Test pH, because Kentucky genuinely contains both sweet and sour ground. In the Bluegrass and Pennyroyal, plant the calcium-tolerant species. On the plateau, plant acid-lovers.

Summers are warm and humid, so give plantings airflow. Fall planting suits the whole state, giving roots a mild winter to establish in.

Confirming what is native to your county

The Kentucky Native Plant Society runs chapters and field trips, and the Kentucky State Nature Preserves Commission documents natural communities and protects remnants, including several Bluegrass savanna-woodland sites that show what the region looked like. University of Kentucky Extension provides county guidance.

Sources: Kentucky State Nature Preserves Commission (natural communities and rare species); University of Kentucky Cooperative Extension (regional guidance); USDA PLANTS Database (native status by state).