I first grew amsonia or bluestar perennial flower years ago in a public garden. I was impressed with the size, stature and beautiful light blue flowers that it produced in early summer and gorgeous golden fall foliage. Bluestar is a native plant that should get more recognition. It was the Perennial Plant of the Year back in 2011, but I rarely see it in gardens.
Amsonia grows 1- to 3-feet tall and wide depending on the selection. It’s an herbaceous perennial, but grows into a small, shrub-like shape with willowy-narrow leaves. There are a few selections of amsonia to consider. Amsonia tabernaemontana is the hardiest and ‘Storm Cloud’ is a nice selection that grows 2-feet tall. ‘Blue Ice’ is a 15-inch tall variety that’s very popular. Amsonia Hubrechtii is a Midwest native that reaches 3 feet tall and wide.
Most bluestar perennials are hardy to zone 5 so grow well in our climate. They grow best in full to part sun in well drained, but moist soil, that’s not too rich. Very fertile soils can cause the plants to flop. Moist soils result in taller plants, whereas drier soils can cause the plant to dwarf.
Plant amsonia in a foundation planting, flower garden or mixed shrub border. It looks best planted in groups where they can support each other and lend a soft, velvety feel to a bed with its feathery foliage. The clumps will spread over time and can be divided in late summer to increase the number of plantings. Enjoy the brilliant yellow fall foliage color and cut back the plant after a frost.