Native Plants for Arkansas

Arkansas has two upland regions and they are not the same thing. The Ozark Plateau in the north is a dissected limestone and sandstone plateau, cut by clear streams, with bluffs and hollows and a flora shared with Missouri.

The Ouachitas in the west-central part of the state are true folded mountains, and unusually they run east to west. That orientation produces long slopes facing consistently north or consistently south, and the difference between them is dramatic: south-facing slopes are hot, dry, and open, carrying pine and dry-site species, while north-facing slopes stay cool and moist and grow a much richer hardwood flora.

If you garden in the Ouachitas, which way your slope faces is the most important fact about your site.

Delta, ridge, and river valley

Eastern Arkansas is Mississippi alluvial plain: flat, fertile, heavy soil, historically bottomland hardwood and cypress swamp, now largely farmed.

Running through that flat country is Crowley's Ridge, a narrow strip of wind-deposited loess standing above the floodplain. It carries a forest with species disjunct from the Appalachians, growing on soil that exists nowhere else nearby.

The Arkansas River Valley separates the Ozarks from the Ouachitas and includes Mount Magazine, the state's high point, along with prairie remnants on the valley floor.

Glades and rocky ground

Like Missouri, Arkansas has glades: openings where bedrock reaches the surface and trees cannot establish. They bake in summer and support drought specialists. A rocky, thin-soiled, south-facing site in this state should be planted with glade species, which hold up there without irrigation while conventional perennials struggle.

Practical choices

Soil chemistry varies with the bedrock, limestone in parts of the Ozarks, sandstone and shale in the Ouachitas, alluvium in the Delta. Test rather than assume.

Summers are hot and humid, and drainage is the key variable. Plant on ground where water moves if you have heavy soil, and choose drought-adapted species for rocky or sandy sites.

Fall planting is the best window statewide.

Confirming what is native to your county

The Arkansas Native Plant Society runs field trips and maintains guidance, and the Arkansas Natural Heritage Commission documents natural communities and manages natural areas across all the state's regions. The University of Arkansas Cooperative Extension Service publishes county-level advice.

Sources: Arkansas Natural Heritage Commission (natural communities and natural areas); University of Arkansas Cooperative Extension Service (regional guidance); USDA PLANTS Database (native status by state).