Ilex aquifolium 'Ferox Argentea', variegated porcupine holly
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Broadleaf Evergreen Shrubs

Ilex aquifolium 'Ferox Argentea'

variegated porcupine holly

Aquifoliaceae

Species native to western and southern Europe, northwestern Africa, and western Asia; cultivar of garden origin

At a Glance

TypeShrub
HabitUpright
FoliageEvergreen
Height10-20 feet (3-6 m)
Width8-12 feet (2.4-3.6 m)
Maturity25 years

Growing Zones

USDA Hardiness Zones

6 - 9
Zone 6
Zone 7
Zone 8
Zone 9
These zones indicate the coldest temperatures this plant can typically survive.
Frost Tolerancehardy

Key Features

Attracts Pollinators
Deer Resistant
Drought Tolerant
Container Friendly
Maintenancemoderate

Overview

A cultivar of Ilex aquifolium forming a dense, upright evergreen shrub or small tree reaching 10-20 feet (3-6 m) tall and 8-12 feet (2.4-3.6 m) wide at maturity. Growth rate is very slow, typically 4-8 inches (10-20 cm) per year, noticeably slower than the species type. This cultivar is distinguished by leaves that bear spines not only along the undulating margins but also erupting from the upper leaf surface, giving a prickly, hedgehog-like texture. Leaves are 1.5-3 inches (4-8 cm) long with irregular cream-white to silver-white margins surrounding a gray-green to dark green center, often with gray-green mottling. The variegation is most pronounced in full sun; plants grown in heavy shade produce leaves with less contrast and more green coloring. This is a male clone and does not produce berries. Young stems are green to purple, becoming gray with age. The combination of surface spines and variegation makes this one of the most texturally distinct holly cultivars. Hardy to approximately 0°F (-18°C). Like the species, it is susceptible to holly leaf miner, though damage is less conspicuous on variegated foliage. Branches that revert to all-green foliage should be removed promptly, as reverted shoots are more vigorous and will eventually dominate if left.

Native Range

The species Ilex aquifolium is native to western and southern Europe, northwestern Africa, and western Asia, ranging from Scandinavia south to the Mediterranean. Found naturally in mixed woodlands, hedgerows, and forest understories from sea level to approximately 5,000 feet (1,500 m). The cultivar 'Ferox Argentea' is of garden origin, first recorded in cultivation in the early 19th century.

Suggested Uses

Commonly grown as a specimen or accent shrub in mixed borders where the variegated, spiny foliage provides textural contrast. Plant at 4-6 foot (1.2-1.8 m) spacing for hedging, though slow growth means hedges take many years to fill in. As a male clone, it serves as a pollinator for female holly cultivars. Suitable for containers of at least 15 gallons (57 L) due to the slow growth rate, though long-term container culture limits ultimate size.

How to Identify

Unmistakable among hollies due to the combination of spines on the upper leaf surface in addition to the marginal spines, a trait shared only with other 'Ferox' cultivars. Leaves are 1.5-3 inches (4-8 cm) long with cream-white to silver-white irregular margins surrounding a gray-green to dark green center. The surface spines are stiff, short projections erupting from the upper leaf blade, giving a distinctly rough, hedgehog-like texture when touched. Distinguished from 'Ferox' (the green-leaved porcupine holly) by the presence of cream-white marginal variegation.

Appearance

Size & Dimensions

Height10' - 20'
Width/Spread8' - 12'

Reaches mature size in approximately 25 years

Colors

Flower Colors

white

Foliage Colors

dark green
gray green
cream
white

Bloom Information

Bloom Period

~3 weeks
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Spring
Small white flowers appear in May to June in axillary clusters on the previous year's wood. Individual flowers are approximately 0.25 inches (6 mm) across. As a male clone, flowers produce pollen but no fruit. Bloom period lasts approximately 2-3 weeks. Flowers are visited by bees but are not the primary ornamental feature of this cultivar.

Detailed Descriptions

Flower Description

White

Foliage Description

Gray-green to dark green center with cream-white to silver-white margins

Growing Conditions

Sun Requirements

Full Sun
Partial Shade
Requires 3-8 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 Range5.0 - 7.0(Neutral)
357912
Soil Types
loamclaysand
Drainage
well drained

Water & Climate

Water Needs

Medium

Frost Tolerance

hardy

Time to Maturity

15-25 years

Drought Tolerance

Drought tolerant when established

Care & Maintenance

Care Guide

Plant in well-drained soil in full sun to partial shade; variegation is most pronounced in at least 4-6 hours of direct sunlight per day. In heavy shade, leaves develop with reduced variegation and more green coloring. Water regularly during the first two growing seasons; established plants tolerate moderate dry periods but leaf drop may increase during prolonged drought exceeding 3-4 weeks. Watch for all-green reverted shoots, which arise occasionally from the base or interior; remove these promptly at their point of origin, as they are more vigorous than variegated growth and will overtake the plant if left. Holly leaf miner causes serpentine mines on leaves; damage is cosmetic. Protect from cold, desiccating winter winds in exposed sites.

Pruning

Prune in late winter to early spring before new growth emerges to shape and remove dead or damaged wood. Responds to shearing for formal shapes, though the slow growth rate means less frequent trimming is needed compared to the species — typically once or twice per growing season rather than three to four times. Remove any all-green reverted branches immediately at their point of origin regardless of season. Hard rejuvenation pruning to 12-18 inches (30-45 cm) is tolerated but recovery is very slow, taking 3-4 years to fill in.

Pruning Schedule

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winterearly spring

Maintenance Level

moderate

Container Growing

✓ Suitable for container growing

Minimum container size: 15 gallons

⚠️ Toxicity Warning

Toxic to pets and humans