Baptisia australis (blue false indigo), like all of the false indigo, is easy to grow, drought tolerant, hardy across a huge swath of the U.S., and attractive to bees and butterflies. More, it is a native perennial.
I cannot fathom how many photographs I have taken of blue false indigo. It is a favorite plant and somehow the images never measure up. Today, my children Flynne and Ian were behind me, clamoring for a picture of a bee, never mind the Baptisia.
Finally, I took a good photograph of blue false indigo by taking a picture of a bee for my children.
Blue false indigo may be the finest false indigo of all. The flowers are regal blue and stand strong on very stout stems. Blue false indigo grows to 4 feet tall with a similar spread. It is a big plant. Baptisia australis blooms in mid-spring, reaching its peak as the roses and foxglove come into bloom.
Some sources recommend the need to stake blue false indigo. I have never needed to stake a false indigo of any kind. In my experience, if you need to stake a blue false indigo it is growing in way too much shade.
Blue false indigo blooms a tad later than other false indigos, such as yellow false indigo, white false indigo, and some of the hybrids like Carolina Moonlight and Praireblues Twilite. You grow all of these in the garden with similar technique. For me, this means lots of sun and don't sweat the rest.
False indigo grows well in poor soils. It grows well in great soils. Baptisia can handle drought; it can handle lots of rain. Stay away from poorly drained soils if possible. Shade is acceptable but you risk floppy plants. Whatever you do, be patient and give blue false indigo a couple of years to really get going.
Blue false indigo is hardy zones 3-9.
As mentioned in my other writings on the subject of Baptisia, false indigo sprawls all over the place after blooming. Give false indigo room to spread and/or plant it in the back of the border. Blue false indigo has a deep root system and does not tolerate transplanting.
I've read recommendations to use blue false indigo in naturalized gardens and it is often used in this manner. Most often you see false indigo grown in a casual manner standing all on its own. False indigo is a weirdly formal plant in some ways, most likely because it grows fairly stiffly.
Frankly, there is nothing special about the lower half of false indigo. I much prefer to surround false indigo of all types with plants of similar height and breadth. One of the prettiest displays of false indigo I have seen was Carolina Moonlight tucked behind a relatively tall growing dark Penstemmon digitalis.