This outstanding perennial is still not commonplace, but it’s steadily gaining in popularity thanks to several new hybrids. Both the native form and the hybrids are worth growing. All are highly rated by horticulturalists and gardeners alike. If you’re not familiar with it, read on and find out why.
Bluestar (Amsonia) is a small genus in the dogbane family. It consists of a handful of native species found primarily in central, southern and eastern parts of the US. Two species in particular and their cultivars are widely available, which I will discuss here; the rest are wildflowers.
Arkansas bluestar (Amsonia hubrictii) also called Hubricti’s or threadleaf bluestar, is best known for its textural foliage and fantastic fall color. It is trouble-free and long lived. Slim yet bushy foliage rises quickly to a height of 30 inches with pale blue flowers appearing at the top in mid-May. The fluffy look makes a perfect foil for just about any companion plant imaginable. A cheerful chartreuse in summer, the entire mass turns brilliant yellow and deep gold in fall.
- String Theory – A commercially available hubrictii nativar with threadleaf foliage and pale blue flowers. It is very much like the native form (which is usually identified simply as “hubrictii”).
Eastern bluestar (Amsonia tabernaemontana) has a more robust presence with larger leaves than hubrictii but is otherwise similar in height and habit. This species boasts several hybrids.
- Storm Cloud – A profusion of soft blue stars adorn smoky stems and handsome olive foliage. With more flowers per stem in a soft shade that goes with everything, this hybrid makes an elegant statement. Fall foliage is a nice clear yellow but not as spectacular as hubrictii. A very beautiful choice. Mature clumps reach 24 – 30 inches tall and wide, which stay neat and tidy.
- Blue Ice – This shorter blue-violet variety works great in front of the border. Dark purple buds create a pleasing two-tone effect in bloom. The emerald foliage is lush and upright, almost milkweed-like. (It does produce a white sap when cut, so handle with gloves.) While individual flowers are larger than the species, there are fewer of them, so mass it for best effect. A great choice for covering fading bulbs with yet more color!
- Stainless Steel – Another tabernaemontana hybrid with pale silvery flowers on medium green foliage. A quiet mixer for toning down strong colors or blending with other pastels. Nice yellow fall color.
Siting and Cultivation
Bluestar is one of those rare plant-it-and-forget-it perennials, another reason it’s so highly rated. Being native or native-derived, bluestars are tough, adaptable and unfussy. Pest and disease free, they can be planted under black walnut trees, in full sun or part shade, in any kind of soil. They tolerate storms and climate extremes like drought, heat and cold really well. Long lived and well behaved, they are utterly carefree. What’s not to like!
Provide at least a half day of sun: the more sun, the better the fall foliage color will be. Plants will flop in too much shade or excessive rainfall. A trim of 6 inches after flowering will keep stems upright and bushy if flopping is a concern. Space about 18 inches to 2 feet apart. Cut spent foliage to the ground in fall or winter before spring shoots emerge. (Wear gloves; all bluestars exude an irritating white sap similar to milkweed.) There’s rarely a need to divide it.
That’s it! So easy.
Companions
Pretty much everything and anything goes with bluestar. I spot it in public botanical gardens all the time because it’s so useful as a filler.
Storm Cloud would look stunning with white peony, apricot exbury azalea, pink lilies or even roses. Blue Ice could mingle with short alliums and late narcissus. Hubrictii’s chartreuse, grassy texture is fantastic for setting off whatever you pair with it. I have a Rainbow Ascot euphorbia, pink phlomis, roses, butterflyweed, daffodils, and conifers with mine. The sky’s the limit!
Do try bluestar. It makes a terrific middle of the bed filler for those inevitable bare spots, and the flowers look just as good in arrangements as they do in the garden. Bluestar might not be the first thing you notice, but it will enhance everything else.
Now, where can I find room for Storm Cloud?
