English Holly Hedge Plants (Ilex aquifolium)

A dense native evergreen hedge

English holly (Ilex aquifolium) is a native evergreen that holds its dark, glossy leaves through every season. Its closely spaced branches and prickly leaves gradually form a thick boundary, with sheltered places among the foliage where birds can roost and nest. Holly can be clipped into a crisp formal line or left to develop a softer, more natural outline where space allows.

Young holly plants put on height gradually, usually growing more slowly than Leylandii. With time and regular trimming, they develop the dense evergreen growth needed for a well-shaped hedge. Taller plants give you more height from the outset, although every size needs careful watering while its roots settle into the surrounding soil.

Why choose English holly for hedging

English holly hedging plants have stiff, prickly leaves that can discourage people from pushing through a boundary. As the branches thicken, the hedge also provides shelter from wind and nesting cover for garden birds. Its native foliage stays green throughout winter, when many other hedges are bare. Female holly plants can produce bright red berries from autumn into winter if their flowers are pollinated by a male plant nearby. Berry production depends on the sex and maturity of the plants, so grow holly primarily for its evergreen foliage rather than expecting berries on every plant.

Height, spread and growth rate

You can maintain an established English holly hedge at around 1.2m to 4m tall with regular trimming. An unclipped plant may eventually reach 10m or more over many decades, so allow enough room for its mature growth. Once established, holly typically adds around 15 to 30cm a year, depending on soil, moisture and growing conditions. Individual plants can spread to around 4m if left alone, but clipping the sides each year keeps a hedge at a manageable width.

Using holly in the garden

Plant holly hedge plants along a boundary, beneath a window where prickly foliage is useful, or beside an exposed part of the garden where a thick hedge can help slow the wind. You can also grow individual plants as evergreen shrubs among other border planting. Because the leaves are prickly, avoid planting immediately beside narrow paths or where children play. Wear gloves when handling or trimming, and keep clippings cleared away.

For a dense, even hedge, follow the single-row planting distances below. If you have room for a wider hedge, a staggered double row helps the foliage fill out across a greater depth.

Choosing a size

Our English holly plants come in 9cm pots, with three heights available: 30-40cm, 40-60cm and 60-80cm. Smaller plants are useful when planting a long stretch of new hedge, while taller plants provide more height straight away. All three sizes are supplied pot-grown, ready for planting into prepared soil. Minimum order is 10 plants per size.

Compare the starting heights and suggested planting densities below to work out which size suits your hedge.

Leaves, flowers and berries

English holly produces small, creamy-white flowers in spring. On female plants, these may develop into red berries if a compatible male holly is flowering nearby. Male plants do not produce berries, and fruiting also depends on plant maturity and growing conditions. The dark green, glossy leaves, usually edged with sharp spines, remain on the branches throughout the year. Holly grows well in sun or partial shade, in moist but well-drained soil. The berries are ornamental and must not be eaten.

When and how to plant

You can plant pot-grown holly hedge plants throughout the year, provided the ground is not frozen or waterlogged. Autumn and spring are particularly suitable because the soil is generally moist. Clear weeds from a strip at least 60cm wide, then water each pot thoroughly. Take the plant out of its pot and place the rootball in the planting hole with its surface level with the surrounding soil. Backfill, firm the soil gently around the roots and water thoroughly to settle the soil.

Spacing and quantities

For a single row, allow 4 to 5 plants per metre at 30-40cm, 3 to 4 at 40-60cm, or 2 to 3 at 60-80cm. For a thicker hedge, plant two staggered rows 30 to 40cm apart, positioning the plants in one row between those in the other. The quantities below cover common hedge lengths using 5, 4 or 3 plants per metre respectively.

Watering and feeding

Water regularly throughout the first full growing season, checking that moisture reaches the roots rather than just wetting the soil surface. Holly foliage can shed rain away from the base of the plants, so check the soil during dry spells even after light showers. Spread a 5 to 7cm layer of organic mulch over the planting strip, leaving a clear gap around each stem. If feeding is needed, apply a balanced slow-release fertiliser or a handful of fish, blood and bone per plant in early spring, following the product instructions.

Trimming calendar

Give a formal holly hedge its main trim in late summer (August to September), once the strongest flush of growth has slowed. Cut back new shoots to maintain the outline, keeping the base slightly wider than the top so light reaches the lower branches. Check carefully for nesting birds before starting and leave any occupied nests undisturbed. Wear sturdy gloves and long sleeves when cutting or collecting the prickly foliage. Holly berries are toxic if eaten, so remove clippings and fallen berries from places where children or pets play.