Monday, November 19, 2012

Symphyotrichum georgianum – Georgia Aster

Symphyotrichum georgianum - Georgia aster
This exceptionally deep violet-purple form of the Georgia aster is the cultivar 'N3 Purple Haze'.

Georgia aster (Symphyotrichum georgianum) is a colonial, rhizomatous perennial with flowering stems 1.5–3 feet (50–100 centimeters) tall. It is listed by the USDA as occurring in Alabama, Florida, Georgia, Louisiana, North Carolina, and South Carolina. In Florida, it is a rare plant that is listed as occurring only in Leon County by the Atlas of Florida Vascular Plants.

On March 17, 2006, I acquired a small plant of the deep violet-purple cultivar 'N3 Purple Haze' and planted it in a sunny site in well-drained sandy soil. It quickly spread by way of underground rhizomes to form a patch that covered about 1.5 square feet (0.4572 square meters). To my surprise, the colony has never grown beyond those 1.5 square feet even though there are no obstacles or larger plants preventing its spread. Thus far, it has not been attacked by the aphids, caterpillars, mealy bugs, scales, nematodes, grubs, or viruses that prove so troublesome in south Florida.

Symphyotrichum georgianum - Georgia aster
New stems of Georgia aster emerge in early spring.

Georgia aster flowers abundantly and spectacularly but it is among the last of the wildflowers to bloom in my garden and begins to flower at the end of October or the beginning of November. The only other wildflower in my garden that blooms later are my clones of Symphyotrichum concolor (eastern silver aster) from Miami-Dade County, which do not flower until the end of November or even December. After flowering, the stems dry up and I remove them. Unlike some asters, the stems of Georgia aster tend to recline, or even lie on the ground, with age. Gardeners who desire a more formal appearance can trim back the plant in mid-summer, a treatment that results in shorter, more erect flowering stems.

Like most rhizomatous perennials, Georgia aster is easily propagated by splitting off and potting up new growths in the spring. My single plant has never set viable seed, which indicates that Georgia aster is self-sterile. This year I've acquired a second clone and I'm hoping to obtain viable seed next year. The new clone has flowers of the typical color for the species, deep blue rather than purple-violet, and I'm hoping that, by crossing the two, I will get progeny whose flowers will come in a range of blue, violet, and purple colors. Craig Huegel has images of plants with the typical deep blue flowers at his blog, Native Florida Wildflowers.

Symphyotrichum georgianum - Georgia aster

Images and text © 2012 Rufino Osorio

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