Acanthus spinosus aka Spiny Bear's Breeches

Acanthus spinosus is a perennial in the acanthus family, Acanthaceae. Gardeners call it bear’s breeches or spiny bear’s breeches. Its native range runs from southeastern Europe to southern Türkiye. It grows in temperate regions and forms a spreading clump. Garden plants reach 3–4 feet [0.91–1.22 metres] tall. Spread ranges from about 3–4 feet [0.91–1.22 metres].

The leaves form a mound below the upright flower stems. Each leaf can reach 2–3 feet [0.61–0.91 metres] long. They arch out from a rosette at ground level. The green blades are glossy, deeply lobed, and edged with stiff spines. Their shape gives the plant a coarse, bold look. The leaves fall away rather than staying green year-round. Their form inspired leaf designs on Greek Corinthian columns.

White flowers sit in rows along tall, sturdy spikes. They resemble snapdragons and have a lipped, tubular shape. Spiny bracts surround each bloom in pink, mauve, or reddish purple. The spikes rise above the leaves, reaching 3–4 feet [0.91–1.22 metres]. Flowering runs from late spring into the middle of summer. Chicago Botanic Garden lists a broader season, from May through August. The flowers attract butterflies and suit cut-flower arrangements. Dry seed pods follow the blooms.

Grow this plant in sun or partial shade. Shade from afternoon sun helps in hot summer climates. It accepts sand, loam, and clay when water drains well. Wet, poorly drained ground does not suit it. Give it moderate water in cultivation. Chicago Botanic Garden lists USDA zones 5–9; NC State lists zones 7–10. Missouri Botanical Garden warns that zone 5 plants may not survive winter. It advises winter mulch there. Plants need little routine care, though new clumps can establish slowly.

Use bear’s breeches in borders, cutting gardens, or as an accent. Its leaves and tall blooms give beds a strong outline. It also serves as groundcover or an understory plant. Roots can spread strongly once the plant settles in. Small root pieces left behind can grow into new plants. This makes an established clump hard to remove. Growers can raise plants from seed or spring root cuttings. Slugs and snails can cause serious damage to the leaves. Powdery mildew can also affect the plant. It tolerates rabbit damage, and Chicago Botanic Garden lists deer resistance.