The familiar garden aster serves as a vital food source for countless insects. With few other perennials blooming in the fall and most flowering plants beginning to prepare for winter dormancy, the prolific blossoms of myriad asters are a necessary piece of the wild food chain. The New England aster (Symphyotrichum novae-angliae) is a smaller, rounded plant growing well in moist prairies, stream banks, and disturbed areas. Growing between 3-6’, most often 4’, the New England aster makes a statement in the fall garden when planted en masse. The airy, pubescent foliage is covered with 1” diameter, purple, daisy-like flowers beginning in late September and continuing into November. Symphyotricum novae-angliae is very adaptable in the garden, though it may drop its lower leaves in hot, dry conditions. Various bee and butterfly species will visit asters for their abundant nectar and pollen production. The New England aster attracts a number of moth species that utilize this plant as a larval host. These droves of pollinators are crucial to the survival of the New England aster as the seed produced will be sterile unless individual plants are cross-pollinated. Deer and rabbit will occasionally browse the foliage of Symphyotrichum novae-angliae, but it is not a preferred food source. Placed at the front of a perennial border where it can spread to form small colonies, the New England aster will dazzle in the garden during the fall months when little else is flowering.
Another aster species, the smooth aster (Symphyotrichum laevis), displays a more upright and loose habit. Growing to 5’ in height, the smooth aster features smaller individual blooms (0.5-1” diameter) produced at the terminal ends of tall, erect flowering stems. Growing in virtually any condition, Symphyotrichum laevis spreads readily from seed but don’t worry about it taking over as it gives in quickly to surrounding established plants. Smooth aster stays surprisingly strong under the weight of its blossoms and continues to hold its stature into the winter. Symphyotrichum laevis is another pollen and nectar buffet for pollinators in fall and the lavender to light-blue flowers begin in mid-September persisting into late October. Pearl Crescent butterfly larvae feed on the foliage of smooth aster as does the Short-Winged Meadow Katydid adult. With proper siting and consideration for the weedy nature of this aster species, smooth aster can be an excellent addition to a meadow garden or other naturalized area.
A more common and often more weedy aster is the heath aster (Symphyotrichum ericoides). Unlike the smooth aster, the heath aster spreads via underground rhizomes. Eventually, the plant can become a nuisance, creeping underground to emerge a few feet away and proving difficult to pull from the garden. However, the profuse blooms are of great importance to pollinators. This is easily observed on a warm fall day when hundreds of bees, butterflies, wasps, and other insects are voraciously feeding on the copious amounts of pollen and nectar produced by the small (1/4-1/2” diameter) flowers. Beginning in early fall and lasting into late fall, the blooms are attractive in large groupings, but can appear weedy and open as standalone plants. The Silvery Checkerspot butterfly uses Symphyotrichum ericoides as a larval host along with a long list of moth species. Be very careful when siting heath aster as it will become an aggressive, garden brute if not controlled. The heath aster often hybridizes with other aster species, resulting in variability in size and flower color (sometimes a light pink or purple tint).
Compiled by Cara L. Crocker