Aromatic Aster
Photo by Matt Whitaker
Scientific Description: Aromatic Aster – Symphyotrichum oblongifolium – is a member of the Aster (Asteraceae) family and is native to much of the eastern and central areas of the United States. This herbaceous perennial prefers drier, poor soils and full sun, but it can tolerate moist or wet soils, so long as they are well drained. This plant’s stiff stems grow to a height of about two-three feet (and similar spread) and branch repeatedly from the basal rosette of leaves.
The showy flowers of Aromatic Aster have blue or purple petals with a yellow button-like center flower and don’t show until very late in the autumn – late August through October. Contrary to the common name, this species’ flowers are NOT fragrant; however, the leaves are, with a sweet, pungent smell.
This species requires a medium amount of annual maintenance and is often used as a ground cover. It does best in Hardiness Zones 3 – 8. While it has no major disease or insect problems, this species can be susceptible to mildew, often a result of limited air movement.
Photo by Matt Whitaker
Habitat Value: This species attracts many pollinators, including bees, butterflies and other insects, as well as small birds (feeding on the small seeds), and small mammals. It mostly reproduces via stolons, underground stems that emerge from the soil some distance from the mother plant and begin a new plant.
Landscape Value: By Matt Whitaker of WMWA Landscape Architects
Aromatic aster is one of our last blooming native flowers providing pollinator forage late into October, when there is little else available. Like many other asters, its blooms are a joy for people who are missing the vast flowers of summer. The leaves, when brushed lightly, release a pleasant fragrance, as the name suggests.
For these reasons, I include asters in every project allowable. Aromatic aster is usually at the top of my list for inclusion because it is one of the toughest and most vigorous plants I’ve planted. In Virginia, I planted a few plugs in late spring, watered them once, then forgot them as life got busy. A few months later, I remembered them and found them not only alive, but four or five times larger than the plugs I had planted! One of the photos I shared for this post are those plugs in their second year. Few plants are as vigorous without being too aggressive.
Matt’s Virginia garden
While I have seen seedlings in irrigated gardens, this aster seldom gets aggressive. The individual plants do get large, so I use two-foot spacing, which is another bonus for planting budgets. They do sometimes need a late spring pruning for the best results, as they can be leggy by fall without it. This depends on the garden, so you should see how they perform for one year without pruning.
Raydon’s Favorite is perhaps the most popular cultivar of aromatic aster, and it is my favorite, as well. It is readily available in the horticultural trade and has larger and more blooms than the straight species.
There is much misunderstanding about plant cultivars. Many are selections from the wild that had superior characteristics and are not the result of breeding programs. The vast majority are not sterile or lacking in seed or nectar, so they provide all the ecosystem benefits. While they do limit genetic diversity in the larger landscape, they provide a lot of benefit by displaying qualities that most homeowners want, ultimately making the case for removal of non-native ornamentals and lawn easier and increasing overall diversity. The diversity among individual plant species can also be addressed by using multiple cultivars and, where appropriate, the straight species in our gardens and landscapes.
