Plant of the Week
Arkansas Blue Star
Latin: Amsonia hubrichtii
 Choosing perennials for the garden is serious business
because each of us works with a finite amount of space. We want a long
ornamental display plus a measure of toughness that insures a long and carefree
life in the garden. Arkansas Blue Star is a plant that meets these criteria.
Arkansas Blue Star gives you the durability of the best natives and the grace
and charm of a well refined perennial, all while providing an effective display
from spring through fall. For these reasons, and because it’s not well known
among gardeners, Arkansas Blue Star was named as an Arkansas Select Plant for
2001.
Arkansas Blue Star grows up 3-feet tall with its stems arising from a
crown. The graceful branches arch outward from the crown and spread 4-feet wide
on mature plants. The leaves are linear, up to 3-inches long, and almost
grass-like in appearance.
In the summer, these lacy plants provide an interesting textural foil for
other plants in the garden. In the fall, the foliage turns a golden yellow and
persists for about three weeks. The plant is most beautiful season in the fall.
Flowers appear in late April and May. They’re often described as "sky blue,"
but that would have to be on a very hazy day because they tend to be light blue
to almost white. The flowers are borne terminally in a panicle and they hide in
the foliage at the top of the plant.
Individual flowers have the typical 5-pointed star associated with the
Amsonia and are about three-fourths of an inch across. The seed pod is an
elongated, cigar-shaped follicle about the size of a large toothpick.
Gardeners familiar with Arkansas native plants are most likely familiar with
the other Blue Star, A. tabernaemontana. The common Blue Star has a wide
range of distribution throughout the Eastern woodlands. It has a much more
robust habit than the Arkansas Blue Star. It has grown almost a foot taller and
twice as wide in the three years it’s been grown in the Horticulture Garden on
the U of A campus. But it only shines when in bloom and has no fall color.
Amsonias belong to the dogbane family along with Vinca minor and the
common periwinkle. Like many members of that family, they have a milky sap. The
sap of some species in the family contain toxic alkaloids that have been used
medicinally and can be toxic to livestock. For the gardener, this is good.
Amsonia are often listed as "deer-proof" plants.
Arkansas Blue Star’s native range is the Ouachita mountains of
Arkansas and Oklahoma. The species was only recognized as distinct in 1943 when
a botanist from the Missouri Botanic Garden grew material provided by Leslie
Hubricht, an expert on fresh water mollusks. Hubricht had been on a collecting
trip for the Field Museum of Natural History in Chicago the year before when he
ran across the unusual Amsonia in Garland County.
Like most Amsonia, this species is adapted to any well drained site in either
full sun or shade. It does best with an acidic pH but is not generally
considered finicky about soil conditions. The first year after planting,
Amsonia hubrichtii will look a bit spindly and unpromising. This
establishment period can be shortened by amending the soil with lots of organic
matter and providing good cultural management.
Allow the clump a couple years to fully expand and its beauty will be a thing
to behold, especially in the fall.
By: Gerald Klingaman, retired
Extension Horticulturist
- Ornamentals
Extension News -
June 28, 2001
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