As fall comes to New England, asters come into their own, blooming from August into October in a range of colors–blues, pinks, purples and white–with some varieties flowering after frost. They can be tall or short, thrive in sun or shade, and thrive in damp or dry conditions. Cardinals, chickadees, nuthatches and finches enjoy their seeds. Asters get high marks for beauty, ease of care, and attractiveness to pollinators. They are the mainstay of many a fall garden.
The name aster comes from a Greek word meaning star and refers to the daisy-like petals. Aster flowers look like ordinary, single flowers but are in fact remarkable, composite flowers. The “petals” are individual ray flowers whose own petals are fused; the round center (disc) consists of anywhere from dozens to hundreds (!) of individual florets. Ray flowers are usually sterile; their job is to attract passing pollinators with their UV-reflecting color, guiding them onto the disc.
Previous Columns
The many florets that make up the disc, on the other hand, have pollen and nectar. When you think that each disc may have hundreds of florets it is easy to see how attractive these composite flowers are to pollinators. Imagine for a moment you are a passing pollinator (bee, fly, skipper, moth, wasp, beetle, or butterfly, you choose). You catch sight of the beckoning ray flowers and alight to find a compact circle of tightly packed florets, a late season buffet.
The aster family, Asteracae, is huge, second only to orchids, with some 32,000 species worldwide—there will likely be an aster to suit every gardener’s taste. I quite like these plants:
New England aster, Symphyotrichum novae-angliae, has profuse, showy, purple or pink blossoms with golden yellow centers (August through September) that make good cut flowers. This tall (to six feet), robust, meadow plant grows well in average soil in full sun. No meadow? Plant it at the back of the border and pinch it back before July to tame its height. Pinching will encourage more blooms but may delay the onset of flowering, you might want to leave some stems untouched.
Smooth blue aster, S. laeve, is a more manageable size, growing 18 inches to three feet, in loose clumps, in part to full sun and dry to medium soils. The heavily petalled flowers bloom late summer into fall and are a lovely cornflower blue with bright yellow centers; a good addition to a mixed border.
Calico aster, S. lateriflorum, may reach three feet in height. Grow it in sun to part sun; its ability to thrive in dry to moist soil conditions make it useful for rain gardens. The small white flowers have variously colored centers (hence “calico”) and are usually all on one side of a branching stem. causing the plants to lean.
Blue wood aster, S. cordifolium, has heart-shaped leaves and blooms in fall. The narrow rays of the blue flowers are airy in appearance and the center is purplish red. A good plant for a dry woodland garden, it thrives in poor soil and prefers shade,
White wood aster, Eurybia divaricata, has dense clusters of bright white flowers with yellow centers which turn red after pollination. Like blue wood aster, the foliage is heart-shaped. This plant prefers shade and is drought tolerant. It spreads slowly to form compact clumps.
Big-leaved aster, E. macrophylla, (sometimes called lumberjack toilet paper) has large, fuzzy, heart-shaped leaves and grows to about one foot in height, with flower spikes reaching 18 inches. This aster also prefers shade or part shade and is not fussy as to soil or moisture. Big-leaved aster spreads by rhizomes, the large pale leaves make a good ground cover. The flowers may be white or pale violet, blooming August through October.
And lastly, flax-leaved stiff aster, Lonactis linariifolia. This is a pretty little thing. It grows in low clumps, averaging about one foot in height. The dark green foliage resembles pine needles and the late-summer blooms are a soft violet with gentle yellow centers. This plant likes it sunny and dry and prefers sandy or gravelly soil; it is intolerant of rich or moist soil, making it a nice choice for a rock garden.
Dorothy gardens in Belmont where she lives with her husband, Steve, and their two dogs, Rosie and Jasper. She has six grandchildren — all perfect by definition — and has enjoyed introducing them to gardening. She has an abiding interest in nature and is always amazed by the wonders to be found in her own backyard.
