Eastern Blue Star (Blue Dogbane)

Amsonia tabernaemontana

Apocynaceae

• Full sun to part shade (best form & bloom in full sun)
• 2'–3' tall × 2'–3' wide (clump-forming)
• Drought Tolerance: Moderate; drought tolerant once established, prefers moist, well-drained soil; tolerates clay
• Flower: Powder-blue, star-shaped clusters (May-July)
• Wildlife Benefits: Butterflies, long-tongued native bees, hummingbird moths, hummingbirds; deer & rabbit resistant

Eastern blue star belongs to the dogbane family (Apocynaceae) and is native to the eastern and southern United States, ranging from Virginia south to Florida and west to Illinois and Texas, where it grows in moist woodlands, along stream banks, and in open fields. It grows in full sun to part shade, though the flower display and the sturdiest, most upright habit come with more sun. While it prefers moist, well-drained loam, it tolerates clay and becomes moderately drought tolerant once established. In shadier or richer sites, plants can flop after flowering; trimming the top several inches of growth after bloom keeps the clump neat and showcases the foliage.

In late spring to early summer, pyramidal clusters of small, soft powder-blue, star-shaped flowers open at the tips of erect, leafy stems, the massed blossoms reading as much larger flower heads from a distance. The narrow, willow-like foliage stays clean and attractive all summer, then turns a striking golden yellow in fall, giving the plant a second season of interest. Clump-forming and growing to roughly 2 to 3 feet tall and wide, it develops a rounded, increasingly distinguished mound with age. Upright seed follicles add a subtle vertical accent after bloom.

The nectar-rich flowers attract butterflies, long-tongued native bees such as carpenter bees, hummingbird moths, and ruby-throated hummingbirds. The stems and leaves exude a milky latex when cut, a characteristic of the dogbane family that makes the plant unpalatable to deer and rabbits and gives it good browse resistance. * That same sap is mildly toxic if ingested, though it is not a significant hazard in the garden.

Blue star works as a specimen in an informal or cottage-style planting, as a transitional mass at a woodland edge, or in a mixed perennial border where its spring blue and gold fall color extend the season. Because it appreciates a bit more moisture than the true xerics, place it in the moderate-water zones of a design rather than among dry-loving natives. Its yellow autumn foliage pairs handsomely with late-season asters and goldenrod, and its cool blue spring bloom complements catmint (Nepeta faassenii), blanket flower (Gaillardia aristata), and coneflower (Echinacea).