Native Plants for Delaware

Delaware is small and mostly flat, and its one significant geological boundary runs across the top of the state. North of it, around Wilmington, a narrow band of Piedmont brings rolling terrain, rock near the surface, and clay soils. South of it, the Atlantic Coastal Plain takes over and does not stop until the ocean.

That coastal plain is sand and sandy loam, generally acidic, fast-draining, and low in nutrients. It supports a flora of oak and pine woodland, with Delmarva bays scattered through it: shallow seasonal wetlands that fill in winter, dry by midsummer, and hold a specialized set of plants adapted to that cycle.

For most Delaware gardeners, then, the working assumption is sandy acidic ground, and the plant list should follow from that rather than from a generic mid-Atlantic list.

Water on three sides

The Delaware River and Bay, the Atlantic, and the inland bays put a lot of the state near salt or brackish water. Tidal marsh species belong in the transition zones, and salt tolerance is a real requirement along the coast where wind carries spray inland.

Sea level and groundwater are close to the surface across much of the state, so low spots stay wet longer than their soil texture suggests. Read the site in early spring before deciding what goes there.

Planting into sand

The reliable approach on coastal plain soil is to plant species that evolved on it and skip the amendments. Butterfly weed, little bluestem, blazing star, and the oak-woodland understory plants all handle lean, dry, acidic ground and resent enrichment.

Mulch with leaf litter where possible rather than heavy bark, which sheds water on sandy sites. Water through the first season only.

Delaware's season is long and its winters mild by regional standards, which makes fall the clearly better planting window nearly statewide. Roots keep working into December in the south.

Confirming what is native to your county

The Delaware Native Plant Society maintains guidance for the state, and the Delaware Department of Natural Resources and Environmental Control documents natural communities and rare species. Mt. Cuba Center near Hockessin is a significant regional resource: its native plant trial garden publishes rigorous comparative research on how native species and their cultivars actually perform, which is unusual and directly useful when choosing between them.

Sources: Delaware Department of Natural Resources and Environmental Control, Natural Heritage Program (natural communities); Mt. Cuba Center (native plant trial research); USDA PLANTS Database (native status by state).