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Content Detail

Spiny bear’s breeches is a bold, 3 to 4 foot high perennial with large, shiny, thistle-like leaves. Spikes of white with mauve flowers tower above the foliage in early summer. A good back of the border plant or to use as a specimen. Plants grown in northern climates benefit with a layer of winter mulch.

  • Family (English) Acanthus
  • Family (botanic) Acanthaceae
  • Tree or plant type Perennial
  • Native locale Non-native
  • Size range Large plant (more than 24 inches)
  • Light exposure Partial sun / shade (4-6 hrs light daily)
  • Hardiness zones Zone 5 (Northern Illinois), Zone 6 (City of Chicago), Zone 7, Zone 8, Zone 9
  • Soil preference Moist, well-drained soil
  • Tolerances Clay soil, Dry sites
  • Season of interest early summer
  • Flower color and fragrance Purple
  • Shape or form Arching, Mounded, Upright
  • Growth rate Slow

Size and form:

Spiny bear’s breeches is a mounded narrow plant reaching 3 to4 feet high and 4 feet wide. 

Native geographic location and habitat:

It is native to the eastern Mediterranean, from Italy to Greece, Turkey, and Algeria.

Leaf description:

Spiny bear’s breeches has large, deeply cut, pinnately compound leaves. They are thistle-like with a sharp spine at the tip. Each leathery leaf is 18 to 24 inches long and shiny with most of the foliage mounded at the base.

Flower arrangement, shape, and size:

The mauve-purple and white, trumpet-shaped flowers are born on a 2 to 4 foot high flower stalk in early summer.

Fruit, cone, nut, and seed descriptions:

The fruit is not ornamentally significant.

Plant care:

Best planted in part shade and well-drained, organic, rich soil although it will tolerate clay soil if there is good drainage. Plants benefit from morning sun and afternoon shade. In cool summer climates, plants will tolerate more sun and drier conditions. In northern climates, add a layer of mulch to protect the root system in winter. Deadhead flower stalks by cutting back to the ground, but wait to cut back dead foliage until spring. It can be aggressive in sandy soils.

List of pests, diseases and tolerances:

Possible problem can include slugs and snails, powdery mildew, and root rot in wet soil.


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