Amsonia hubrichtii (Arkansas Bluestar)

Arkansas Bluestar (Amsonia hubrichtii) is a widely-planted Arkansas endemic ornamental, named for amateur botanist Leslie Hubricht who first described it in 1942. In the wild the species is a narrow endemic of the Ouachita Mountains of central Arkansas and adjacent eastern Oklahoma, where it is globally rare. It is NOT native to Oregon or the Pacific Northwest. We grow it because it is a beautiful, well-behaved garden perennial that won Perennial Plant of the Year 2011, but we want to be straight that this is an Arkansas plant, not a regional native.

Mature plants form three to four foot rounded clumps of threadlike narrow leaves, fine enough to look like green clouds in summer. In May into early June, terminal panicles carry pale steel-blue five-pointed star flowers above the foliage, lightly fragrant and visited by bumblebees, native bees, and butterflies. The summer texture alone is enough to recommend the plant in a perennial border.

The fall color is what made Amsonia hubrichtii famous. In October the entire mound of threadlike foliage turns brilliant gold-yellow, brighter than almost any other perennial in the trade, and holds the show for weeks until the first hard frost. In the right siting the plant becomes a glowing autumn focal point.

Plant in full sun in average to lean, well-drained soil. Drought-tolerant once established. Tolerates clay. The rounded habit needs no staking and the milky latex sap of the Apocynaceae family deters deer. Cut back hard in late winter for clean spring regrowth. USDA Zone 4 to 9.

Pairs naturally with Schizachyrium scoparium, Symphyotrichum oblongifolium, Sporobolus heterolepis, Echinacea purpurea, and Rudbeckia hirta for an ornamental perennial border that leans on prairie and Eastern North American natives. For a true PNW-native blue-flowered perennial alternative, consider Camassia quamash or Penstemon serrulatus.