Common Name: bear's breeches
Type: Herbaceous perennial
Family: Acanthaceae
Native Range: Mediterranean
Zone: 5 to 9
Height: 3.00 to 4.00 feet
Spread: 2.00 to 3.00 feet
Bloom Time: June to August
Bloom Description: Pink - mauve
Sun: Full sun to part shade
Water: Medium
Maintenance: Low
Flower: Showy, Good Cut
Leaf: Colorful
Other: Thorns
Tolerate: Rabbit
Culture
Easily grown in average, medium, well-drained soil in full sun to part shade. Tolerates wide range of soils except poorly-drained ones. Appreciates some afternoon shade in hot summer climates such as St. Louis. Not reliably winter hardy throughout USDA Zone 5 where a winter mulch is advisable. Easily grown from seed or may be propagated by root cuttings best taken in early spring. Can spread aggressively by creeping rootstocks, particularly in loose soils. Can be slow to establish in the garden, but somewhat difficult to eradicate once established since small sections of root left behind can sprout new plants.
Noteworthy Characteristics
Acanthus spinosus, commonly called bear's breeches, is a clump-forming perennial which is grown as much for its attractive foliage as for its architecturally bold flower spikes. Features pure white, snapdragon-like flowers enclosed (hooded and subtended) by spiny, reddish-purple bracts and arranged in vertical rows on substantial flower spikes which rise well above the foliage mound to 3-4' tall. Blooms from late spring into mid summer. Deeply-cut, arching, glossy green, spiny, thistle-like leaves (2-3' long) form an ornamental mound of long-stalked, basal foliage which usually remains attractive throughout the growing season. Similar in appearance to Acanthus hungaricus ( A. balcanicus), except the leaves of A. spinosus are more deeply cut and have rigid spines (hence the species name) at the lobe tips.
Acanthus leaves have a classical appearance and were the source of the Corinthian leaf motif developed and used as a decoration in ancient Greek and Roman art and architecture.
Genus name comes from the Greek word akantha meaning spine in reference to the toothed edges on leaves in some species.
Specific epithet means spiny in reference to the rigid spines on the leaves.
Problems
Susceptible to powdery mildew. Snails and slugs are occasional visitors that can do substantial damage if left unchecked. Plants can spread aggressively in optimum conditions.