Amsonia hubrichtii

Amsonia hubrichtii produces clusters of soft blue, 1/2-inch star-shaped flowers. Photo: Walters Gardens Inc.

Amsonia hubrichtii (blue star) is the Perennial Plant Association’s 2011 Perennial Plant of the Year. Native to central Arkansas, the plant produces soft, alternate needlelike green leaves during the spring and summer. During the fall the leaves turn a bright golden yellow. In April and May plants produce 2-to 3-inch clusters of soft blue, ½-inch star-shaped flowers on 3-foot tall stems.
 
Plants reach 3-foot tall and wide in the landscape. The plant’s bright yellow foliage makes it a good backdrop for fall-blooming perennials. It is hardy in USDA Hardiness Zones 4-9.
 
This species is named for American biologist Leslie Hubricht who found the plant growing in the wild in the 1940s.
 

Amsonia hubrichtii is available as #1 grade bare root plants from Walters Gardens. The bare roots, which have five to eight eyes, can be planted into 1-gallon containers filled with a well-drained growing medium with a pH of 5.6-6.2. The bare root should be planted with the crown just below the soil surface.
 
After plants are watered in the growing medium should be allowed to dry thoroughly between waterings. After new leaves have emerged apply a water soluble fertilizer with 50-100 parts per million nitrogen at each or every other irrigation.
 
Maintain a growing temperature of 55°F-65°F. Plants do not need to be pinched, but trimming or pinching back after flowering finishes increases the plant density.
 
The only pest concerns are Mycosphaerella leaf spot and rusts. 

 
For more: Walters Gardens, (888) 925-8377; www.waltersgardens.com. Perennial Plant Association, (614) 771-8431; www.perennialplant.org.