Symphyotrichum patens (late purple aster)

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Symphyotrichum, Genus, patens, Species,

Genus & species

late purple aster

Asteraceae Central and eastern United States

Attracts Pollinators Attracts Butterflies Drought Tolerant Container Friendly

SunFull Sun – Part Shade

WaterLow · drought-tolerant

HardinessZones 4–9

Overview

Symphyotrichum patens is an upright herbaceous perennial growing 1-3 feet (30-90 cm) tall on slender, rough-hairy stems that branch widely in the upper half. The leaves are 1-4 inches (2.5-10 cm) long, oblong, rough to the touch, and clasp the stem with rounded, ear-like bases. Daisy-like flower heads about 1 inch (2.5 cm) across are carried singly at the ends of spreading branches, each with 15 to 25 violet to blue-purple ray florets around a yellow central disc that ages to reddish-purple. Flowering runs from August to October, late in the season after many other wildflowers have finished. The plant grows in dry, open woods, clearings, prairies, and roadsides across the central and eastern United States. It is drought tolerant once established and grows in lean, well-drained soils. The stems often lean or sprawl in rich soil or shade. A limitation in formal plantings is this loose, open habit, which can look untidy without nearby plants for support.

Native Range

Symphyotrichum patens is native to the central and eastern United States, from Massachusetts and Minnesota south to Florida and Texas. It is common in dry, open woods, prairie edges, and disturbed sunny ground.

Suggested Uses

Grown in native plant gardens, meadows, prairie plantings, and the middle of mixed borders for late-season colour, spaced 18-24 inches (45-60 cm) apart. Suited to dry, sunny banks and naturalised areas. The late flowers supply nectar for migrating butterflies, bees, and other autumn pollinators.

How to Identify

Recognised by its violet to blue-purple, daisy-like flower heads on widely spreading branches, opening late in summer and autumn. The rough, oblong leaves clasp the stem with rounded, ear-like lobes at the base. Its clasping leaves and loose, open branching separate it from other blue asters.

Appearance

Size & Dimensions

Height1' - 3'

Width/Spread1' - 2'

Colors

Flower Colors

Foliage Colors

Bloom Information

Bloom Period

~10 weeks

Flowers: August–October

Fall

Violet-blue flower heads open from August to October, among the latest of the native asters to bloom. The flowers appear singly at the tips of spreading branches over several weeks. Bloom continues until frost in many areas.

Detailed Descriptions

Flower Description

violet to blue-purple with yellow center

Foliage Description

green

Growing Conditions

Sun Requirements

SunFull Sun SunPartial Shade

Requires 6-12 hours of direct sunlight daily

• Full Sun: 6+ hours of direct sunlight

• Partial Shade: 3-6 hours of direct sunlight

• Full Shade: Less than 3 hours of direct sunlight

Soil Requirements

pH Range5.5 - 7.5 (Acidic to alkaline)

3579

Soil Types

sand loam rocky

Drainagewell drained

Water & Climate

Water Needs

Low

Frost Tolerance

hardy

Drought Tolerance

Drought tolerant when established

Care & Maintenance

Care Guide

Symphyotrichum patens grows in full sun to part shade and dry to medium, well-drained soils, including sandy and rocky ground. It establishes from seed or division and tolerates heat, drought, and poor soil once rooted. Rich soil and shade produce taller, weaker stems that sprawl. Little supplemental water is needed after the first season. Cutting the stems back by half in early summer produces a denser, more self-supporting plant.

Pruning

Stems can be cut back by about half in late spring or early summer to limit height and reduce flopping. Spent stems are cut to the ground after frost. Dividing clumps every few years keeps them growing strongly.

Pruning Schedule

Prune: June

late springsummer