White wood aster

Sun

Partial shade is ideal; tolerates deeper shade with fewer flowers, or some sun if the soil stays moist.

Water

Water regularly during establishment. Once rooted, it tolerates moderately dry soil; water during prolonged drought if leaves wilt persistently.

Soil

Well-drained soil, preferably enriched with leaf mould or compost. Tolerates a range of soil textures and pH levels, but not prolonged waterlogging.

Height

1.5-3 ft (0.45-0.9 m)

Spread

1.5-2.5 ft (0.45-0.75 m), spreading farther over time

Flowers

Late summer to autumn; small white daisies with yellow centres that age to reddish purple.

Foliage

Green, toothed leaves; lower leaves are heart-shaped with long stalks, while upper leaves are smaller and narrower. Slender stems are often dark purple.

Growth

Moderate; spreads by short rhizomes and self-seeding.

Care needed

Low

• Pollinators
• Drought tolerant
• Cold hardy
• Wildlife
• Low allergen

Northern hemisphere months. In Australia, shift them by six.

Difficulty

Easy

Toughness

Very tough

Pick your zone, country, light and whether you have pets.

1. Planting day

   1 ft (0.3 m)

2. After 1 year

   1.4 ft (0.43 m)

3. After 2 years

   1.8 ft (0.55 m)

4. After 3 years

   2.2 ft (0.68 m)

   full size

About 3 years to full size.

From a typical nursery size, at an average rate for this kind of plant. A rule of thumb, not a forecast.

Cats and dogs

Safe

Native to

the US and Canada

In the garden

Spreads vigorously: plan to contain it.

Growth rate

Moderate

• Water newly planted clumps through their first growing season, especially beneath trees.
• Apply a thin layer of leaf mould or compost in spring, keeping it clear of emerging shoots.
• Avoid heavy feeding, which encourages tall, floppy growth.
• Divide crowded clumps in spring every three to five years, or when they outgrow their space.
• Remove unwanted seedlings and lift spreading edges where a firm boundary is needed.

Pruning. Leave stems standing through winter for seed-eating birds and insect shelter, then cut them to ground level in late winter or early spring before new shoots lengthen. To reduce self-seeding, remove flower heads before the seeds ripen.

Late winter

Cut old stems to ground level before new growth begins.

Spring

Plant or divide clumps and water them in thoroughly.

Spring

Add a thin mulch of leaf mould or compost and remove unwanted seedlings.

Summer

Check new plants during dry spells and water deeply when needed.

Late summer

Check flowering stems for flopping; support discreetly if necessary.

Autumn

Leave seed heads for wildlife, or remove them before seed dispersal to limit spread.

• Plant in drifts beneath deciduous trees to brighten dry, lightly shaded ground in late summer.
• Weave through ferns and sedges for a loose woodland planting with contrasting leaf shapes.
• Use along shaded paths, allowing the branching flower stems to soften the edges.
• Combine with blue-flowered woodland asters and goldenrods for a late-season pollinator border.

Garden styles it suits: Woodland, Wildlife garden, Pollinator garden, New perennial (prairie), Low-maintenance and White garden.

Plant it with: Christmas fern, Pennsylvania sedge, Barrenwort, Solomon's seal, Blue-stemmed goldenrod and Blue wood aster.

Wildlife: Flowers provide late-season pollen and nectar for bees, butterflies and other insects. Seeds are eaten by small birds, and standing stems offer shelter for overwintering insects.

• Powdery mildew can coat leaves in dry, crowded conditions; thin congested clumps, improve airflow and water the soil during drought.
• Slugs and snails may damage young shoots; inspect new growth and remove pests or use iron-phosphate bait according to the label.
• Stems may flop in rich soil or deep shade; avoid high-nitrogen fertiliser and move plants to brighter shade if flowering is weak.
• Roots can rot in persistently wet soil; improve drainage or move the plant rather than continuing to water.

Not known to be toxic to people, cats, dogs or horses. Species-specific toxicity information is limited, so do not treat any part as food or allow pets or livestock to eat large quantities.

• Blue wood aster (Symphyotrichum cordifolium)

  Also has heart-shaped lower leaves, but usually bears pale blue to lavender flowers in taller, more upright sprays rather than loose, white-flowered branching clusters.

• Bigleaf aster (Eurybia macrophylla)

  Forms conspicuous patches of much larger, broad basal leaves; its flowers are usually pale lavender, though they can be nearly white.

• White heath aster (Symphyotrichum ericoides)

  Has narrow, almost needle-like leaves and densely branched flower sprays, rather than the broad, heart-shaped lower leaves of white wood aster.

The epithet divaricata means widely spreading or branching, referring to its branching habit, while white wood aster describes its flower colour and woodland habitat.

Propagation. Divide clumps in spring, keeping roots and several shoots on each division. Sow seed outdoors in autumn or give it a period of cold, moist conditions before spring sowing; seedlings may differ from named cultivars.

Accepted botanical name

Eurybia divaricata

In the US and Canada

Native in Canada and the lower 48 states.

Native range

Alabama, Connecticut, Delaware, District of Columbia, Georgia, Kentucky, Maine, Maryland, Masachusettes, Michigan, New Hampshire and New Jersey.

Sources: GBIF (CC BY 4.0), USDA PLANTS and Trefle (CC BY 4.0). The care and design notes are LandscapeGPT's own.