Blue star requires soil that doesn’t dry out. Before planting, add organic matter (such as well-aged compost) to the soil. Mulch with 2 to 3 inches of pine needles or shredded bark to retain moisture.
Grown in part shade, the plants will grow new foliage if the flower stems are cut to about half their height after blossoms have faded. Stems bleed a milky sap when cut (see page 119). Plants rarely need dividing, but to increase your supply, divide into 4- to 6-inch clumps in spring before the brittle shoots start to emerge.
Blue star, also called willow amsonia, is a tidy plant with a long season of interest. In late spring, clusters of starry steel blue flowers appear atop 24- to 36-inch stems. Slender seedpods similar to those of milkweed but not as spectacular follow the blossoms. Then, at summer’s end, the shiny, dark green willow-shaped leaves turn vivid yellow—guaranteed to brighten the dreariest fall day. This star performer requires little attention to keep it happy, although a nod of approval now and then won’t go amiss.
ZONES: 3–9
BLOOM TIME: Late spring
LIGHT:Full to part sun
HEIGHT: 24–36 inches
INTEREST: Clusters of steel blue star-shaped flowers; bright yellow foliage in autumn
Plant in full sun or part shade (advisable in the South). To fully appreciate the beauty of the flowers, give blue star a place at the front of a border. It is most attractive when placed in front of plants with bold foliage such as peonies, hostas, or oak-leaf hydrangeas. To enjoy the fall color to its fullest, plant blue star alongside plants with bronze or copper foliage.