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.

Wednesday, April 2, 2008

Spring Blooming Ground Cover: Green and Gold (Chrysogonum virginianum)

We are rennovating here in Atlanta including elimination of our existing 1980s deck and expansion of an exsisting patio to create a more fitting outdoor room for our 1930s bungalow home. As one change inevitably leads to another, I’m been moving plants that are in the way and planning revisions to the gardens that will surround the patio.

One of the plants I’m relocating is a large patch of Green and gold – one of the few native groundcovers we have that works in shade. The first thing that struck me about the plant was how fast it spreads.

When I purchased this plant in spring 2005 it was growing in a one gallon pot. Just two years later it had spread to fill a space nearly five foot by five. In looking at species account online, I find that many sources list the spread as infinite. That’s a great investment if you have a large area to fill quickly.

The Details
Appearance – Green and Gold is a semi-evergreen plant (more so in the warmer portion of it’s range) with hairy leaves and many five petaled yellow flowers rising above the foliage. A Northern variety is a much taller upright specimen than the prostate creeper found here in the south, which usually tops out at three to six inches.
Bloom time – beginning in late March through the fall – more sporadically in the heat of summer.
How it grows – individual plants spread from above ground runners and division is the easiest method of propagation. In fact, division every couple of years is quite beneficial to the plant.
Preferred environment – the most important criteria is well drained soil with filtered shade or morning only sun. Deep shade will result in minimal blooms and full sun will require substantial irrigation. Zones 5-9
Native Range – found throughout most of the Eastern United States, but endangered in Kentucky and Pennsylvania and threatened Tennessee and Ohio
Derivation of name – a member of the aster family, the name for Chrysogonum is derived from the Greek chrys meaning gold and gon meaning offspring. It is also sometimes known as Goldenstar.

The Nursery
Because this project is happening in stages, many of the plants I’m moving can’t be transplanted to their new locations until after the new patio is built. I’ve created both a sun and a shade nursery to carry them over until they can go back into the ground. Friends and family are also going to benefit from the overflow.

So far, I’ve only dug up about 1/3 of the Green and gold, and I already have 11 gallon pots and two full flats of a four inch pots. Likewise with Small Sundrops Oenothera perennis. I have a couple dozen pots of this great sun perennial from the evening primrose family.