Overview

Acanthus spinosus is a columnar upright herbaceous perennial in the genus Acanthus, part of the Acanthaceae family, with deciduous foliage. It typically grows around 1.5 metres tall and 0.6–0.9 metres wide. Acanthus spinosus grows best in full sun and partial shade, and tolerates well-drained and fertile soils and neutral and alkaline pH. Its UK hardiness is rated H5. Suggested uses include borders, architectural planting and mediterranean gardens. It is native to Mediterranean.

About

Acanthus spinosus is an herbaceous perennial that reaches about 1.5 metres and is valued for its summer flower spikes. Native to the Mediterranean, it flowers from June to August. It forms clumps 0.6–0.9 metres across and prefers well‑drained, fertile soil of neutral to alkaline reaction. Suited to full sun or partial shade and used in borders and architectural plantings.

Wikipedia contributors, CC BY-SA 4.0 — Acanthus spinosus

About the genus

Acanthus is a genus of about 30 species of flowering plants in the family Acanthaceae, native to tropical and warm temperate regions, with the highest species diversity in the Mediterranean Basin and Asia. This flowering plant is nectar-producing and depends on butterflies, such as Anartia fatima, and other nectar-feeding organisms to distribute its pollen. Common names include acanthus and bear's breeches.

Wikipedia contributors, "Acanthus (plant)", CC BY-SA 4.0 — Acanthus (plant)

In the garden

Acanthus spinosus belongs to the Acanthaceae and originates from the Mediterranean. It grows to roughly 1.5 metres tall and makes a clump 0.6–0.9 metres wide, producing its main display in summer; flowering takes place from June to August. The common name Spiny Bear's Breech reflects its long association in cultivation. Give Acanthus spinosus a sunny or part‑shaded position on well‑drained, fertile soil with a neutral to alkaline pH. It prefers soil that stays reasonably moist without waterlogging. Plant on a south or west aspect where possible; it tolerates both sheltered and more exposed sites. It is rated H5 for UK hardiness, meaning it is hardy in most gardens. Use it as a structural element at the back of a herbaceous border, as a specimen for architectural planting or in Mediterranean-style beds. Its summer flowering provides vertical emphasis behind lower perennials and grasses. Flowers appear reliably in June–August, giving a clear seasonal window for colour and form in the border.

Growing conditions

Best soil and position for Acanthus

Sunlight

full sun, partial shade

Soil type

well-drained, fertile

Soil pH

neutral, alkaline

Soil moisture

moist, well-drained

Aspect

south, west

Exposure

sheltered, exposed

UK hardiness

H5

Plant details

Acanthus spinosus size, habit and characteristics

Plant type

herbaceous perennial

Habit

Columnar upright

Foliage

Deciduous

Height

1.5 metres

Spread

0.6–0.9 metres

Suggested uses

borders, architectural planting, Mediterranean gardens

Native to

Mediterranean

Care notes

Pruning and caring for Acanthus spinosus

Cultivation

Prefers well-drained soil in full sun or partial shade. Tolerates dry conditions once established.

Pruning

Cut back old flower stems after flowering to encourage fresh growth.

Propagation

seed, division

Pest resistance

Slugs, Snails

Disease resistance

Powdery mildew

Frequently asked questions