Monday, April 28, 2008

Plant Profile: False indigo (Baptisia australis)

Nursery Update
What a difference a few weeks make. At the beginning of the month, I had just started to dig the plants that were in the way of renovations. Now more than three weeks later, we are still waiting on the City of Atlanta to issue a permit for our new patio, the nursery spots we selected to hold over shade and sun perennials are overflowing and everything else is up and blooming.

Though we are still suffering a level 4 drought here in the Piedmont region of Georgia, we fortunately had a great deal of rain over the weekend, which has left everything looking lush and me eager to get planting. Ah well. In the absence of a renewed nearly native garden to show you, let’s talk about one of my favorite native plants that is just starting to pop in an undisturbed area of the garden.

False Indigo (Baptisia australis)
Baptisia is a stiking member of the pea family that blooms here in my garden from late April through early June depending on the species. This photo taken today doesn’t do it justice as the deep indigo blue flowers are just starting to pop out, and you can see how many more there are to come on each flower stalk. These three to four foot tall flower spikes rise high above the trifoliate (three leaflets) foliage mound of blue green leaves.

How it grows
Native to the United States, Blue false indigo or Wild blue indigo is present in all of Eastern, Central and Southern states with the exception of Louisianna and Mississippi, though it may have been introduced to New England. While it is present in a wide range the plant is classified as threatened in Indiana, Maryland and N. Carolina, endangered in Ohio and of special concern in Kentucky. As the common name suggests, this plant was used by early settlers as a substitute for indigofera, a dyestuff from the West Indies.

Baptisia will self sow, and seed can be collected when seed pods turn charcoal black and seeds can be heard to rattle within. These seeds can be directly sown in the ground in the fall or in the spring. However, older seeds will benefit from immersion in boiling water to begin to breakdown the hardened seed shell. The tough roots can also be divided in fall or early spring while the plant is dormant. If sown from seed, the plant may take up to three years to bloom but once established will form a spreading colony that is three to four foot wide. The preferred environment is full sun with well drained soil, however Baptisia will accept part day shade and drier soils, and has proven quite drought tolerant here in Atlanta.

Though B. australis bears dark blue to purple flowers, other species and cultivars are commercially available with white, yellow and smoke (white crossbred with blue) flowers. The flower shape is reminiscent of a lupine bloom or that on an English pea. In my garden, the white plant (B. alba) blooms a bit earlier. This photo taken today shows that the bloom is quite advanced compared to its neighbor.

Seasonal interest
I’m always looking for native plants that provide multi-season interest and Baptisia does not disappoint. If not cut back after bloom time dark charcoal colored seed pods will develop which provide interest in the garden, great additions to dried flower arrangements, and wonderful rattles for the amusement of children and pets.

Having said that, False indigo is on the FDA’s list of toxic plants. There have been no reports of poisoning in humans and none in animals since a report published in 1930. Also, it is supposed to be quite unpalatable to animals. Nevertheless, close supervision is required in the garden as both toddlers and puppies tend to explore their environment with their mouth. Even if the worst that happens is a belly ache, it is best avoided.

More information
Check out this Plant Delights Nursery webpage for Tony Avent’s wonderful article on the different species, hybrids, and selections of Baptisia.

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