Sometimes the best plant recommendations come from our neighbors.
Amsonia tabernaemontana
In the Midwest, Missouri has its Plants of Merit and Nebraska has GreatPlants, which highlight the best plants for gardeners in those states. Almost all of their recommendations would do well in Indiana gardens, too.
Plants of Merit is a cooperative venture among the Missouri Botanical Garden, Powell Gardens, Mizzou Botanic Gardens and University of Missouri Extension. The Nebraska Statewide Arboretum manages the GreatPlants program. Each year, members of these groups vote on the best performing and reliable plants for their regions.
One perennial that made both 2009 lists is a top-notch beauty in the Hoosier garden, too.
Arkansas- or threadleaf blue star (Amsonia hubrichtii) is a beautiful, three-season perennial that blooms in late spring. Its finely cut, rich green foliage turns a lovely reddish-gold in fall. It gets about 3 feet tall and wide and does best in full sun in average to moist, well-drained soil. It tolerates light shade and dry soil.
Arkansas blue star (Amsonia hubrichtii) in fall. Photo courtesy PerennialResource.com
This really fabulous perennial gives the best show when planted as a cluster of three. It also can be used as a low-growing summer hedge.
This species has a garden-worthy sister plant, the Eastern blue star or willow amsonia (A. tabernaemontana). The flower and fall color are similar, but the foliage on this perennial is coarser and larger.
The willow amsonia also is 3-feet tall and wide but it’s a bit bulkier, which allows for use as a specimen in the perennial or shrub border. The cultivar ‘Short Stack’ is 12 inches tall and 18 inches wide. ‘Blue Ice’ is 15 inches tall and 24 inches wide.
Gardeners with a sensitivity to latex will want to wear gloves when working with this plant. When cut, amsonia exudes a white, sticky substance. I usually cut amsonia back to the ground in late fall or early winter. These amsonias are native to the Eastern United States and each is winter hardy to USDA Zone 5. They are available at garden centers or from online or mail order retailers.
I grow the willow amsonia in my garden and when it is blooming with its beautiful blue flowers, everyone wants to know what it is.