Baptisia tinctoria is a wildflower native to North America. Also called "wild indigo" or the "horseflyweed," this bushy, evergreen shrub features small yellow flowers that bloom from spring to early fall. Baptisia tinctoria is a desirable plant for home gardeners because of its hardy nature and the unique, blue-green color of its clover-shaped leaves. Once established, this plant lives a long time and requires only basic culture.
Baptisia tinctoria shrubs do well in both warm and cold climates and are hardy to U.S. Department of Agriculture growing zone 3. They grow in the wild from southeastern Canada into New England and as far west as and south as Louisiana and Florida, according to the University of Texas.
Plant baptisia tinctoria in a location where it will receive a full day's worth of sunlight, according to information published by the Missouri Botanical Garden. It will tolerate some shade but flowers best in full sunlight, which is defined as at least six but preferably eight to 12 hours of sunlight each day. The benefit of increased flowering is increased butterfly activity, as the flowers attract butterflies.
Soil and Water
Baptisia tinctoria grows best in sandy or loamy soil, according to the University of Texas. This plant grows in the wild on dry, hot prairies and is very drought-tolerant, so the soil should be allowed to dry down to 1 to 2 inches below the surface between waterings. The soil also should be well-draining. Standing water or otherwise overly wet conditions can lead to root rot, a fungal disease that attacks the roots of the plant and eventually kills it.
Shape the shrub after blooms begin to fade by giving it a trim. This will also remove the possibility of seed pods developing, although some home gardeners enjoy the sound the seed pods make when they rattle in the breeze. The first frost of autumn will turn the blooms an unsightly black color, so cut the shrub down almost to the ground in early fall.
Baptisia tinctoria is a hardy shrub that does not suffer from any major diseases or insect problems, according to Missouri Botanical Gardens. Still, they can suffer from minor insect pests such as aphids or mites. Treat your plant with an insecticidal spray or soap if you notice a large amount of insect activity on your plant.