Amsonia Information – Care and Maintenance

Basic information about Amsonia.  Includes Origin, Growing & Cultivation, Common Pests & Diseases, Interesting Facts & Uses,  and Garden Design Tips.

Amsonia Origin

amsonia hubrichtiiAmsonia, or Blue Star, is native mostly to North America (with 1 species in the Mediterranean and 1 in Asia).

The common name, Blue Star, is derived from the five-petalled, star-shaped blue flowers.

The botanical name, Amsonia, was given in honor of John Amson, an American physician and mayor of Williamsburg, VA in the 1700s.

Growing and Cultivation

amsonia hubrichtii 2Amsonia prefers rich organic soils and plenty of water – do not allow them to dry out!  Water deeply once a week in dry periods. Can tolerate full sun if given enough water, but prefers partial shade.  Too much shade will cause plants to grow longer stems and ‘flop’ open from the center.  This can be prevented by pruning back by 6 inches or 1/3 of plant growth after flowering.  If your soil is very sandy or clayey, amending it with compost, well-rotted manure, or organic mulch (straw, bark, shredded leaves) is recommended.

Common Pests and Diseases

Amsonia is fairly pest and disease resistant; there are no commonly reported pests or diseases this plant is susceptible to.  It is also deer and rabbit resistant; the milky sap makes it unattractive to eat.

Interesting Facts and Uses

The milky sap can be irritating to skin, so wear gloves when trimming/pruning.

Amsonia’s seed pods can be attractive and used in dried-flower arrangements, while the fresh stems can be used as greenery fillers (alternative to asparagus fern) in floral arrangements.  They do need a brief singeing to stop sap running.

Garden Design Tips

Offers a distinctive shade of blue for the landscape with its blossoms, but grown primarily for its foliage texture and superb fall color.  Considered best when massed along a walkway or stream where its soft, billowy texture and lovely golden fall color can be enjoyed while it sways.  Amsonia can complement larger-leaved plants like peonies and hostas.  The golden yellow fall foliage also contrasts nicely with pink sedum or purple coneflower.  This plant also attracts and feeds butterflies and bees,  and so is a good choice for a pollinator-friendly butterfly or bee garden.  Amsonia hubrictii is also a larval host for the swallowtail butterfly, so you could see caterpillars!


To purchase Amsonia, please visit our Shade Companion Plants Page.