What hardiness zones is Acanthus mollis 'Hollard's Gold' suitable for?

Acanthus mollis 'Hollard's Gold' is a clump-forming perennial reaching 3–4 feet (90–120 cm) tall in bloom with a spread of 3–4 feet (90–120 cm). The typical A. mollis has deep glossy green leaves; this cultivar produces leaves that emerge vivid golden-yellow in spring, transitioning to yellow-green through summer. Leaves are deeply lobed, 12–24 inches (30–60 cm) long, with rounded lobes and a glossy surface. Flower spikes, 3–4 feet (90–120 cm) tall, bear tubular white to pale purple flowers with spiny purple-green bracts from June through August. The plant spreads by fleshy underground rhizomes and, once established, is difficult to eradicate; roots left after removal generate new growth. In partial shade, leaf color shifts from golden-yellow to lime-green. In hot, dry conditions, foliage may go summer-dormant by August. The plant is not reliably hardy below zone 7 and may die back to the ground in zone 6.

Native Range

Acanthus mollis is native to the Mediterranean region, including southern Europe (Portugal, Spain, Italy, southern France, the Balkans) and North Africa, growing in open woodland, rocky hillsides, and disturbed areas with well-drained soils. The 'Hollard's Gold' cultivar was developed through horticultural selection and does not occur in wild populations.

Suggested Uses

Planted in perennial borders, woodland gardens, and Mediterranean-style plantings at 3–4 foot (90–120 cm) spacing. The spreading rhizomatous habit requires management in small gardens or near paths, patios, or lawn edges where root intrusion is undesirable. Suitable for containers of at least 10 gallons (38 L) with drainage, which restricts root spread.

How to Identify

Acanthus mollis 'Hollard's Gold' is distinguished from the species A. mollis by golden-yellow to yellow-green foliage rather than deep glossy green. Distinguished from A. spinosus by the absence of spine-tipped leaf segments — lobes of A. mollis are rounded, not spiny. Flower spikes with white flowers and purple-green spiny bracts, reaching 3–4 feet (90–120 cm), are characteristic of all Acanthus mollis types. The large, deeply lobed leaf shape, 12–24 inches (30–60 cm) long, is distinctive among perennials.

Appearance

Size & Dimensions

Height3' - 4'

Width/Spread3' - 4'

Reaches mature size in approximately 3 years

Colors

Flower Colors

Foliage Colors

Fall Foliage Colors

Bloom Information

Bloom Period

~8 weeks

Summer

Flower spikes emerge in June and bloom through August in zones 7–9. In zone 6, bloom may be limited or absent following die-back winters. Individual flower spikes last 4–6 weeks. Plants may not flower reliably until their second or third year after planting. In climates with cool summers, flowering may begin in May; in hot, dry summers, plants may enter dormancy before completing the bloom period.

Detailed Descriptions

Flower Description

white to pale purple with purple-green bracts

Foliage Description

golden-yellow in spring, yellow-green in summer

Growing Conditions

Sun Requirements

Full Sun Partial Shade Full Shade

Requires 2-8 hours of direct sunlight daily

• Full Sun: 6+ hours of direct sunlight

• Partial Shade: 3-6 hours of direct sunlight

• Full Shade: Less than 3 hours of direct sunlight

Soil Requirements

pH Range6.0 - 7.5(Neutral)

357912

Soil Types

loam sand clay

Drainagewell drained

Water & Climate

Water Needs

Low

Frost Tolerance

hardy

Time to Maturity

2–3 years

Drought Tolerance

Drought tolerant when established

Care & Maintenance

Care Guide

Plant in well-drained soil in a location where root spread can be managed; the rhizomatous root system spreads 2–3 feet (60–90 cm) per year in optimal conditions and root fragments left in soil regenerate new plants. Water weekly during the first growing season; established plants tolerate drought but may go dormant by late summer in hot, dry sites. Foliage color is most intense in partial shade with some protection from afternoon sun in hot climates; full shade reduces color to lime-green. Slugs and snails feed on new foliage in spring. In zone 6, mulch the root zone with 3–4 inches (8–10 cm) of material in fall to improve winter survival. Divide every 4–5 years when clumps become crowded and flowering decreases.

Pruning

Cut flower spikes to ground level after bloom ends in August–September to prevent self-seeding and maintain appearance. Remove dead or yellowed leaves at any time. In climates where the plant goes summer-dormant, cut back brown foliage once plants show signs of re-sprouting. In zone 7 and warmer, old foliage persists through winter and can be removed in early spring before new growth begins.

Pruning Schedule

summerearly spring

Maintenance Level

moderate

Container Growing

✓ Suitable for container growing

Minimum container size: 10 gallons

⚠️ Toxicity Warning

Toxic to pets