Bear's breeches

Sun

Full sun to partial shade; afternoon shade is helpful in hot climates. Deep shade usually reduces flowering.

Water

Water regularly during the first growing season. Established plants tolerate some drought, but leaves may collapse or die back in prolonged summer heat and dryness.

Soil

Deep, well-drained soil enriched with compost; tolerates clay if it does not remain waterlogged. Accepts acid, neutral or alkaline soil.

Height

3-5 ft (0.9-1.5 m), including flower spikes

Spread

3-4 ft (0.9-1.2 m), eventually wider through spreading roots

Flowers

Early to midsummer, sometimes continuing into late summer; white flowers with purple-tinged bracts on upright spikes.

Foliage

Large, glossy, dark green leaves with broad, deep lobes. Often semi-evergreen in mild climates, but loses foliage in cold winters or hot, dry summers.

Growth

Moderate; established clumps can spread vigorously

Care needed

Medium

• Pollinators
• Deer resistant
• Drought tolerant
• Heat tolerant
• Wildlife
• Low allergen

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

Difficulty

Moderate

Toughness

Fairly tough

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

1. Planting day

   1 ft (0.3 m)

2. After 1 year

   2.2 ft (0.68 m)

3. After 2 years

   3 ft (1.1 m)

4. After 3 years

   4 ft (1.2 m)

   full size

About 2 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

Invasive in

the US and Australia

In the garden

Spreads vigorously: plan to contain it.

Growth rate

Fast

• Choose a permanent position away from delicate plants; broken roots can produce new shoots after removal.
• Water deeply during establishment and during prolonged dry spells if you want to retain the foliage.
• Apply a thin layer of compost in spring; avoid heavy feeding, which encourages leaves rather than flowers.
• Mulch over the root area in colder gardens, keeping wet mulch away from the crown.
• Support flower spikes in exposed positions and remove unwanted seedlings promptly.

Pruning. Cut spent flower spikes to the base before seed ripens if you do not want seedlings. Remove frost-damaged or collapsed leaves in late winter or early spring, leaving healthy foliage intact.

Early spring

Remove damaged leaves and check emerging growth for slugs and snails.

Spring

Plant into well-drained soil, water thoroughly and apply a thin compost mulch.

Late spring

Place discreet supports around developing flower spikes in windy gardens.

Summer

Water during extended drought if foliage begins to wilt; avoid keeping the crown constantly wet.

Late summer

Cut off fading flower spikes before seeds ripen and pull out unwanted seedlings.

Late autumn

In colder gardens, protect the root area with a loose mulch while maintaining good drainage.

• Use as a bold foliage clump at the back of a mixed border, with room for its spreading roots.
• Pair with ferns and hostas in bright shade for contrasting leaf shapes.
• Plant against a plain wall or fence where the upright flower spikes stand out.
• Use in a Mediterranean-style courtyard bed with enough soil depth and space for a permanent clump.

Garden styles it suits: Architectural minimal, Mediterranean, Italian / Tuscan, Formal, Woodland and Arts and Crafts.

Plant it with: Japanese anemones, Hardy geraniums, Foxgloves, Hostas, Soft shield ferns and Astrantias.

Wildlife: Flowers attract bumblebees and other large bees able to enter the partly enclosed blooms. Dense foliage provides shelter for small garden animals, including slugs and snails.

• Slugs and snails chew young leaves: inspect at dusk, remove pests and use iron-phosphate bait according to the label if needed.
• Powdery mildew can mark foliage in dry, crowded conditions: improve airflow and water the soil during drought.
• Poor flowering often follows deep shade or excessive nitrogen feeding: provide brighter light and reduce rich fertiliser.
• Waterlogged winter soil can rot the crown and roots: improve drainage or choose a better-drained position.

Not known to be toxic to people, cats, dogs or horses; no part is generally recognised as poisonous. It is not a food plant, and the pointed flower bracts can scratch skin.

Where it spreads. Can spread aggressively by roots and seed, especially in mild climates. It has escaped gardens in coastal California, parts of southern Australia including Victoria and South Australia, and New Zealand. Keep it away from natural vegetation and check local weed guidance before planting.

• Spiny bear's breeches (Acanthus spinosus)

  Its leaves are more finely divided, with narrow, sharply pointed, spiny lobes; Acanthus mollis has broader, softer-looking lobes.

• Balkan bear's breeches (Acanthus hungaricus)

  Usually has narrower, more deeply cut leaves and a more upright habit; Acanthus mollis has broader, glossy leaves with larger lobes.

Acanthus comes from the Greek akantha, meaning thorn, while mollis is Latin for soft, referring to the softer leaves compared with spiny species.

Propagation. Divide in spring or take root cuttings while dormant. Sow ripe seed in pots, but expect seedlings to vary. Even small root pieces left in the ground can regrow, so division or removal may leave persistent shoots.

Accepted botanical name

Acanthus mollis

In the US and Canada

Introduced in the lower 48 states.

Native range

Algeria, East Aegean Is., Greece, Italy, Lebanon-Syria, Morocco, Sardegna, Sicilia, Tunisia, Turkey, Turkey-in-Europe and Yugoslavia.

Measured

Soil pH 7.5 to 8.

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