Boltonia asteroides aka White Doll's Daisy

Boltonia asteroides belongs to the daisy family. This perennial lives for more than one year. Its common names include false aster and false chamomile. It is native to central Canada. Its range also spans the central and eastern United States. It grows in wet meadows, marshes, and roadside ditches. It also grows on stream banks and pond edges. In gardens, its branching stems form a tall clump. It spreads by creeping rhizomes, or stems below ground. It can also spread by seed.

Garden height ranges from 3–6 feet [0.91–1.83 metres]. North Carolina State lists 3–5 feet [0.91–1.52 metres]. Missouri Botanical Garden gives a usual height of 5–6 feet [1.52–1.83 metres]. Plants spread 2–3 feet [0.61–0.91 metres] wide. The stems stand upright but may need support. Narrow leaves have a lance shape. They grow along the stems in an alternate pattern. Each simple leaf has no stalk or hairs. Their gray-green shade stands out against brighter leaves nearby. Leaves reach about 5 inches long.

Small flower heads grow in groups at the stem tips. Each head is about three-quarters of an inch across. White rays ring a yellow disk at the center. Some plants have pink, lilac, violet, or purple rays. The main bloom season runs from August into October. Missouri Botanical Garden lists blooms from August to September. North Carolina State says blooms can last until frost. The blooms draw butterflies and other pollinators. Spiny fruits form in September and October. These seed-like fruits are called achenes.

Grow false aster in full sun and moist soil that drains well. It tolerates clay, sand, wet ground, and some dry soil. Part shade can cause stems to flop. Rich, moist soil can cause this too. Dry soil keeps plants short but slows growth and cuts blooms. Cut stems back in late spring or early summer to reduce height. This can also mean less need for stakes. Published USDA hardiness ranges vary from 4–9 to 3–10. Seed offers a simple way to grow new plants.

Use this plant in cottage gardens or native gardens. It also suits areas where plants can spread and grow freely. Its height suits the back of a flower border. Its blooms suit cutting gardens and butterfly gardens too. It resists deer, which helps where deer feed on plants. Sources report no major pest problems. Powdery mildew can still occur. Taller stems may still need stakes. Its spread can make it somewhat weedy.