University of Vermont Extension
Department of Plant and Soil Science

Perennial of the Month - June 2000


Amsonia tabernaemontana

(am-so’ni-a)

Common name: Blue Stars, Blue Star Flower, Willow Amsonia

Family: Apocynaceae, Dogbane

Height x Width: 1-3' tall x 3' wide

Growth Rate: slow to moderate clumps

Foliage: alternate, entire, hairy depending on species.

Flowers: variously blue depending on species, star-shaped, bisexual, in terminal panicles in early summer

Hardiness: Zones 3-9, depending on species.

Soil: moderately fertile soil, highly fertile soil causes the plant to fall over; moisture preferance varies with species, but generally well-drained, moist.

Light: full sun to partial shade

Pests & Problems: none serious

Landscape Habit, Uses: massed in borders, natural plantings, adds a lovely blue color to the front or middle of the border, golden yellow foliage in fall.

Other Interest: Genus was named for Dr. Charles Amson, an 18th century scientific traveller in America. Fruit are long, narrow pods (follicles), erect or otherwise depending on species. Plants, as many in this family, with milky sap.

Other Culture: tolerant of many conditions, cut back in fall, and cut back after flowering if in shade to prevent falling over, divide in 8-10 years, otherwise low maintenance.

Propagation: division in spring, soft stem cuttings in early summer with rooting hormone, seed. Seeds require a cold stratification period of 4-6 weeks and/or soaking overnight before they will germinate.

Sources: many including specialty perennial nurseries; Perennial Pleasures Nursery (VT), We-Du Nurseries, Niche Gardens among other mail order sources


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