Many plants come and go, but there are few as striking as Baptisia australis that make passersby near my yard gasp and inquire. Commonly known as blue false indigo, it is native to the central and southeastern United States. This plant’s flowers were once used as a dye.
Like a few others (Dictamnus or gas plant and Amsonia or bluestar), this perennial can be used as a shrub in the garden. It has many virtues.
Baptisia becomes very deep-rooted and can draw moisture from deep below the soil line. It thrives on rainwater alone, no matter how little rain is received. The caution here is that you should plant this in its permanent position, because getting it out of the ground is effectively impossible.
No need for fertilization
Baptisia fixes its own nitrogen. What does this mean?
Plants build specialized structures on their roots called nodules to house and feed bacteria, which in turn fix nitrogen for the plants and assure them a steady supply of food.
This plant never requires fertilizer, even when you plant it for the first time.
Baptisia australis grows 3 to 4 feet high and wide, perfect for urban and suburban landscapes. Keep it in its place by pulling out seedlings in the spring.
This plant attracts butterflies, while being rabbit- and deer-resistant.
This plant can grow in full sun to partial shade, although it is truly best in full sun. It grows well in most soils. Its deep roots also control erosion on slopes.
It grows well in zones 3 to 9 and blooms from about May to June, after which it forms beautiful pods that remain until a sharp frost. Cut it to the ground after frost to prevent excess seedlings. The plant now has been hybridized to produce flowers in colors from pink to purple and yellow to chocolate. There are also varieties of native white and cream baptisia.
Lilies are beautiful planted as garden companions, blooming in summer after the flowers of Baptisia australis have passed.
Donna Mack is a University of Illinois Extension master gardener for Kane County. The “Learning to Grow” column runs weekly during warmer months of the year. Call the extension office at 630-584-6166 for more information. Feedback on this column can be sent to firstname.lastname@example.org.