Acanthus spinosus

Description and Characteristics

Acanthus spinosus, or Spiny Bear’s Breeches, is a bold, architectural herbaceous perennial grown for its dramatic foliage and striking flower spikes. It forms a large clump of deeply cut, glossy green leaves with spiny margins, creating a lush, sculptural base from which tall flower spikes rise in summer.

In mid to late summer, Acanthus spinosus produces upright flower spikes up to 1.2–1.5 metres tall, adorned with two-toned pinkish-purple and white hooded flowers, each backed by spiny, purple-edged bracts. The flowers are long-lasting and highly attractive to bees and pollinators, while also making excellent cut or dried specimens.

The plant itself typically grows to around 90–120 cm in height, with an equal spread. Its strong form, texture, and stately blooms make it an ideal choice for back-of-border planting, classic garden designs, and Mediterranean-inspired landscapes.

• Herbaceous perennial with bold, spiny, deeply lobed leaves

• Tall flower spikes with purple-white hooded blooms, flowering June to August

• Mature height: 90–150 cm; Spread: 75–100 cm

• Excellent for structural planting, architectural borders, and wildlife-friendly gardens

• Tolerant of drought once established

Growing Conditions and Maintenance

Acanthus spinosus is easy to grow and long-lived, thriving in well-drained soil and a sunny or lightly shaded position. It will naturalise well in suitable conditions and benefits from occasional division or root control.

• Light Requirements:

  • Best in full sun or partial shade

  • Tolerates light woodland shade, but flowering is best in sunnier locations

• Soil Preferences:

  • Grows in moist, fertile, well-drained soil

  • Adapts to a wide range of soil types: chalk, clay, loam, or sand

  • Tolerates dry soils once established

• Watering Needs:

  • Water regularly during the first season to help establish roots

  • Once mature, drought-tolerant but benefits from occasional watering in dry periods

• Feeding:

  • Apply balanced fertiliser or compost mulch in spring to support strong growth

  • No feeding is usually needed in fertile garden soil

• Pruning and Maintenance:

  • Remove spent flower spikes in late summer or autumn to tidy

  • Cut back foliage in late autumn or early spring when it dies back naturally

  • Space plants well apart to prevent crowding

• Root Management:

  • Can spread by underground roots; may need to be controlled or divided every few years

  • Not ideal for small borders due to strong root systems

• Winter Care:

  • Fully hardy in Zones 6–9 (RHS H5)

  • Cut back old leaves in autumn and mulch lightly in colder regions

  • Protect new spring growth from late frost with fleece if needed

Garden Uses, Companion Plants, and Design Benefits

Acanthus spinosus is a classic perennial valued for its architectural form and bold texture. It brings strong vertical interest and dramatic foliage contrast to a wide range of garden settings.

• Design Applications:

  • Ideal for back-of-border planting, cottage gardens, and classical landscapes

  • Works well in Mediterranean and dry gardens

  • Stunning as a focal point in mixed borders or massed for bold effect

• Companion Plants:

  • Pair with Nepeta, Lavandula, Salvia, and Perovskia in dry schemes

  • Contrasts beautifully with grasses, Rudbeckia, Achillea, or Echinacea

  • Use with Hosta or Ferns in shadier locations

• Pollinator Benefits:

  • Flowers are rich in nectar and attract bees and hoverflies

  • Valuable in wildlife-friendly and sustainable planting schemes

• Container Use:

  • Not recommended due to deep roots and large size

  • Better suited to open ground or large raised beds

• Pest and Disease Resistance:

  • Generally pest- and disease-free

  • May occasionally suffer from slugs/snails on young foliage

  • Ensure good drainage to avoid winter rot

We currently only deliver within the island of Ireland, other countries can be quoted for by contacting [email protected] or via telephone on 06964084
 

Standard Delivery is FREE on orders over €250*

All standard deliveries will be completed within 5-7 working days via Fastway Couriers, any delay to this delivery time, the customer will be notified by One of our staff.

The in-Store delivery charge will vary compared with online, in-store delivery charge is done on a case by case basis. 

* Only mainland Ireland addresses qualify for free delivery.
 

Live Plants Delivery

Our live plants are packed with care and diligence by our staff, our horticulturists review each plant before despatch to ensure quality is maintained.
Live Plant delivery charges are not calculated on weight but on the space required per package to ensure safe delivery, so delivery charges may vary as some plants require more space than others when packed.
All live plants are despatched within 3-5 working days where possible, our couriers aim to deliver within 48 hours of despatch from our Garden Centre to allow the plant to arrive in healthy condition.
 

Click & Collect

Can’t wait for delivery? Why not try our FREE Click & Collect service? Simply make your purchase online and collect it from our store located in Croagh Co. Limerick. Our staff will contact you by phone when your order is ready for collection (Please allow 24 hours minimum). When collecting your item, call the store on 069-64084. We will then load into your car as required. This service is available in-store 9am – 6pm Monday – Saturday (No collections on Sundays)

Click here for more information about our shipping conditions.

You can pay your online order either by credit card or via Paypal.
If you have any further questions about the online order payment please contact us via ­069 640 84 or mail.