Author: Amanda C.
The False, or Wild, Blue Indigo, Baptisia australis, is in bloom at the Alcove for the first time. Baptisias are a lovely perennial, and they grow big enough to appear more like a shrub in the summer garden. At full size, they can be over 1.5 meters tall and wide. They grow significant taproots, meaning they’re drought-tolerant, but difficult to move. (Hmm, and this one is very close to the snowberry bushes already. Something will have to be done about that. Even experienced gardeners can make mistakes in placement.) Being legumes, they fix nitrogen in the soil. And baptisias are the only known larval food of the Indigo Duskywing butterfly.
Baptisias are an exclusively American genus, ranging across the continent. B. australis is the one which grows the furthest north. Many of the others have white or yellow flowers rather than blue-purple, and cross-breeding has produced hybrids flowering in various purple, bronze and bi-coloured combinations also. The seed pods can be an attractive feature after flowering.
Why ‘Indigo’ in the name, when most species aren’t blue-flowering? It was reported as being used as a substitute for real indigo (also a legume family member), to produce a blue dye. At least one species of Baptisia, B. tinctoria, does produce some blue pigment, but it seems to be a very small amount – one modern dyer who tried it found that a pickup truck bed full of plant material was only able to dye about 30 grams of wool light blue. So it seems that False Indigo, rather than Wild Indigo, is the more accurate common name for the genus.
False Blue Indigo in bloom at the Alcove Garden
Photo: Amanda C.