How to Grow New England Asters

Sun, moisture, and a fall bloom for pollinators

New England aster is easily grown in average, medium, well-drained soil in full sun; it favors moist, rich soil and tolerates clay. It reaches roughly three to six feet tall with an upright, leafy habit.

The payoff is timing: it flowers from August into September with daisy-like blooms of purple rays and yellow centers, feeding butterflies and other pollinators late in the year when nectar is scarce. That late bloom is the whole point of planting it, so pair it with other fall natives for a strong finish.

Give it steady moisture during dry spells — drought stress is what drives both leaf drop and disease.

Pinch it back so it doesn't flop

Left alone, a tall aster flops and needs staking. The fix is pinching: cut the stems back several times before mid-July to control plant height, promote bushiness, and produce more flowers. This is the same idea as the 'Chelsea chop,' shortening the plant early so it rebuilds denser and stiffer.

Pinching may slightly delay flowering, which is a fair trade for a self-supporting, floriferous plant. Stop pinching by mid-July so the plant has time to set buds for its fall show.

Compact cultivars also flop less than the tall species type, and after bloom you can cut plants to the ground to prevent unwanted self-seeding or once the foliage looks tired.

Powdery mildew and the bare lower stems

New England aster is somewhat susceptible to powdery mildew, especially where air is stagnant. Space plants and thin them for good air circulation, and water during drought to reduce stress — the standard cultural defenses, since crowding and dryness make mildew worse.

Separately, the lower leaves naturally tend to brown and drop by late summer, and drought or disease accelerates it. This is largely cosmetic and does not signal a dying plant.

Rather than fight it, plant around it: set shorter perennials in front so their foliage screens the aster's bare lower stems while the flowers bloom above.

Sources

Reviewed 2026-07-18. We cite university Extension, government, and established horticultural sources — and never invent pesticide rates or dangerous treatments.

• Missouri Botanical Garden Plant Finder — Symphyotrichum novae-angliae — Easily grown in average, medium, well-drained soil in full sun, favors moist rich soils, tolerates clay; grows 3–6 feet tall; daisy-like flowers with purple rays and yellow centers bloom August–September; pinching back stems several times before mid-July controls height and promotes bushiness; some susceptibility to powdery mildew and aster wilt, lower foliage can be lost; hardy zones 4–8; flowers attractive to butterflies; may be cut to the ground after flowering to prevent self-seeding or if foliage is unsightly.

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