PL. —Symphyotrichum novae-angliaeBotanical illustration — drop image

Symphyotrichum novae-angliae

New England Aster

SummerFall

3a–8bHardiness zone

Peak bloom windowZone 6b · frost-offset weeks

Winter

Not in bloom

Spring

Not in bloom

Summer

Not in bloom

Fall

Peak bloom

In bloom

Peak bloom windowZone 6b · frost-offset weeks

Winter

Not in bloom

Spring

Not in bloom

Summer

Not in bloom

Fall

Peak bloom

In bloom

Background

New England aster is a native perennial of central and eastern North America that produces dense clusters of purple, pink, or white ray flowers with yellow centers from late summer through hard frost. It is among the most important late-season nectar sources in the region, supporting pollinators at a time when few other species are still in flower.

Without cutting back, plants commonly reach 4–5 feet and flop. Pinching stems back by one-third to one-half in late spring produces a shorter, bushier, self-supporting plant with only a slight delay in flowering. Clumps expand rapidly; dividing every 2–3 years in early spring maintains vigor. The species tolerates average to slightly moist soils and spreads naturally at meadow edges, roadsides, and streambanks. Powdery mildew on lower foliage is common by late summer but cosmetic and rarely affects performance. In the garden, a 2–3 inch mulch layer helps retain moisture and suppress weeds around the base.

Several Native American nations used root decoctions to treat fever and respiratory complaints and burned dried material as a smudge. The species is a documented host for specialist native bees in the genus Andrena and a critical late-season fueling stop for migrating monarch butterflies.

Good companions

Goldenrod Little Bluestem Joe Pye Weed Butterfly Weed Bluestars Sweetspire Mountain Mints Wild Geraniums

Care guide

SunFull sun to part shade

WaterModerate

SoilAverage, well-drained

Spacing24–36 in

Height3–5 ft

Zone3a – 8b

Native RegionAL, AR, CO, CT, DE, DC, GA, IL, IN, IA, KS, KY, ME, MD, MA, MI, MN, MS, MO, MT, NE, NH, NJ, NM, NY, NC, ND, OH, OK, PA, RI, SC, SD, TN, VT, VA, WV, WI, WY

Direct sowFrost hardy

Seasonal tasks

spring

sowDirect sow seeds outdoors in fall to allow natural cold stratification over winter. Alternatively, start seeds indoors 6–8 weeks before last frost on the surface of moist mix; light aids germination.

cutLeave seed heads standing through early winter to provide food for goldfinches and other seed-eating birds. Cut plants to ground level in late winter before new growth emerges.

sowDivide established clumps when new growth is 4–6 in tall. Discard the woody crown center and replant vigorous outer sections at the same soil depth.

summer

watchMonitor lower leaves for powdery mildew as summer humidity rises. Thin crowded stems to improve airflow; mildew rarely affects flowering or plant survival.

watchWatch for aster yellows: distorted, stunted, or yellowing new growth caused by a leafhopper-transmitted phytoplasma. Remove and dispose of infected plants immediately; there is no cure.

cutCut all stems back by one-third to one-half to control height and prevent flopping later in the season. Do not cut after mid-July or flowering will be reduced.

Common problems

Powdery mildew

Symptoms

White or grey powdery coating on leaves — usually starting on older growth in humid conditions or when nights cool.

Treatment

Improve air circulation by thinning plants. Apply neem oil or potassium bicarbonate spray at first sign. Avoid overhead watering.

Aster Yellows

Symptoms

Deformed, greenish flowers, stunted growth, and yellowed foliage. Flower centers may produce tufts of leafy growth instead of normal petals.

Treatment

No cure. Remove and destroy infected plants immediately to stop spread. Control leafhoppers, which transmit the disease, and remove nearby weed hosts.

Fungal leaf spot

Symptoms

Brown or purplish spots on the leaves, often ringed with a yellow halo, that spread and merge in warm, humid, or wet weather; heavily spotted leaves yellow and drop early.

Treatment

Pick off spotted leaves and clear fallen debris to remove overwintering spores. Improve air circulation by thinning, and water at the base so foliage dries quickly. If it persists, apply a copper- or sulfur-based fungicide at the first sign.