Baptisias are wonderful perennials with lovely flowers and great foliage. In early summer, they send up clusters of pealike flowers in shades of blue, purple, white, cream, or yellow. The flowers usually give way to puffy green seed pods that turn a striking black at the end of the season. The pealike blue-green foliage is lovely, too.
- Common name: False indigo
- Botanical name: Baptisia spp.
- Zones: 4 to 9, depending on species
- Size: To 5 feet tall, depending on species
- From: Areas of North America
- Family: Fabaceae (pea family)
- Sun: Full sun or partial shade
- Soil: Moist, well-drained soil is best. The plants tolerate most soils except wet clay.
- Moisture: Plants are drought tolerant.
- Mulch: A layer up to 4 inches deep around the base of the plant reduces competition from weeds and helps conserve soil moisture. Organic mulches add to the soil's structure over time.
- Pruning: Cut the plants back in autumn after freezing temperatures kill the foliage, or leave the stems standing for winter interest and cut back before growth begins in spring.
- Fertilizer: In all but the poorest of soils, the plants don't require fertilizer. In very poor soils, use an all-purpose garden fertilizer in spring.
- Seed: Plant baptisia seed in a cold frame or sheltered spot in the garden as soon as it is ripe (when seed pods turn fully black and begin to split). Germination may be erratic if the seed is kept too long.
- Division: Divide plants in spring. Note: Take care when dividing-the plants have very large, strong root systems.
- Powdery mildew: This fungal disease tends to appear in mid- to late summer. It usually starts as leaf spotting and is followed by a gray, powdery covering on the affected leaves. The leaves then drop from the plant. To deter it, prune the plant to encourage good airflow, and avoid wetting the foliage in afternoons and evenings.
- Rust: It usually looks like leaf spotting. It's followed by small masses of rust-colored powder on the leaves. Infected leaves die by the end of the season. To deter it, avoid allowing moisture to sit on the foliage; make sure there is good air circulation around plants.
- Baptisias have deep root systems and don't usually transplant well. Choose its spot in the garden carefully to avoid moving them.
- Baptisia alba: Grows to 4 feet tall with white flowers in early summer. Zones 4 to 9.
- Baptisia australis: Grows to 5 feet tall with dark blue flowers and puffy black pods. Zones 3 to 9.
- Baptisia pendula: Grows to 4 feet tall with creamy-white flowers and puffy black pods, as well as dark purple-black stems. Zones 5 to 9.
- Baptisia sphaerocarpa: Grows to 4 feet tall with light yellow flowers in early summer. Zones 5 to 8.
- Baptisia ‘Purple Smoke': This hybrid grows to 5 feet tall with dark purple-blue flowers and puffy black pods and stems. Zones 4 to 9.