Baptisia australis, or blue false indigo is a native American beauty. In fact, Europeans used to pay Americans to grow it, for the dye they made from the blue flowers. That's why it's called False Indigo. Indigo was expensive and Baptisia grew like a weed. Baptisia is a member of the pea family and you’ll notice a resemblance in its foliage and flowers, as well as its fondness for cooler weather. Baptisia australis is a standout because of its striking blue flowers.
Common Name:Blue Wild Indigo, False Indigo
Baptisa has an upright, shrubby form. It offers a long season of interest, with flower spikes, seed pods and foliage that is almost never bothered by pests or disease.
- Leaves: Clover-like trifoliate leaves have a blue-green coloring.
- Flowers: Pea-like blossoms start as plump, tight buds. The flowers are borne on long racemes and are a vivid blue, often with flecks of cream or yellow. They are followed by seed pods which further demonstrate they are a member of the pea family. The pods persist and turn black and are often used in flower arranging.
USDA Hardiness Zones 3 - 10
Exposure:Full sun. Baptisia will get floppy without at least 6 hours of full sun light. Full sun also prevents fungus diseases.
4-5' (h) x 3-4' (w)
Bloom Period:Late Spring - Early Summer
- Purple Smoke Baptisia X ‘Purple Smoke- A hybrid with a purple eye in the center of the blue flowers.
- Twilite Prairieblues™ Baptisia × variicolor Twilite Prairieblues™ - A cross between B. australis and the yellow B. sphaerocarpa purple flowers tinged with buttery yellow.
White Wild Indigo Baptisia alba - Similar plant, with white flowers set against dark stems.
Blends beautifully with pastel spring bloomers, like peonies as well as shocking colors. Spiky plants, like iris, salvia and tall alliums, complement both the color and the texture of Baptisia. The blue blossoms bring out the chartreuse of Lady’s Mantle.
Since it is a large plant and it only blooms once, in early summer, be sure to put it somewhere in your garden where its foliage will continue to offer interest.
Pests and Problems:
Fungus diseases such as leaf spot, powdery mildew and rust can occur if grown in crowded, damp conditions.
Weevils have been know to eat and infest Baptisia seeds. This can be a big problem if you are saving the seeds to plant. Always check your seeds before bringing them indoors.
Planting Baptisia: You can start Baptisia plants from seed, but they are slow to establish and it will probably be 3 years before you see flowers. Even a young Baptisia plant will take at least 2 years to get established, before you really start seeing it bloom. On the plus side, they are very long-lived.
Baptisia seeds have a hard outer coating. If you do decide to try growing them from seed, some type of scarification will improve germination. Soaking them in hot water for at least 8 hours prior to scarifying them would be even better. Although, some gardeners have luck simply planting the seeds in the fall and allowing the winter weather to soften the seed coat.
Maintenance:Baptisia requires very little maintenance. Keep it watered regularly for the first year. Once established, Baptisia is very drought tolerant.
You can leave the spent flowers and enjoy the seed heads. The pods are attractive and jingle in the wind. However they can make the plants top heavy and prone to splitting open in the center, especially plants grown in partial shade. You can prevent this by giving your Baptisia a modest shearing after flowering.
Baptisialeaves turn an unattractive black with the first hard frost and the plants tend to collapse by mid-winter, so cutting them back in fall is usually recommended.
More on adding blue flowers to your garden.