False Indigo

False indigo is the native perennial that behaves like a shrub. Baptisia australis builds a rounded, self-supporting clump 3 to 4 feet tall and wide, hardy from Zone 3 through Zone 8 in full sun to part sun. It sends down a deep taproot first and can take three seasons to reach full size, which is the trade for a plant that then holds its shape year after year without staking, dividing, or any real attention.

Spikes of indigo-blue pea flowers rise above the foliage in late spring, filling the gap after the early bulbs finish and before the summer perennials start. Bumblebees are heavy enough to force the flowers open, which smaller bees cannot manage.

The charcoal-black seed pods that follow are as ornamental as the flowers and rattle on the stems into winter. The blue-green foliage stays clean and structural through the whole season, which is not something most perennials manage by August.

False indigo feeds wild indigo duskywing and frosted elfin caterpillars. Deer avoid it, and once the taproot is down it handles drought and moderate salt without help. That same taproot means it will not transplant well after the first year or two, so put it where you want it to stay.