Slow-Growing Hedging Plants for UK Gardens

Slow-growing hedging plants give you a neat, evergreen boundary with far less trimming. Yew, holly and box grow about 10-30cm a year, so one cut in late summer keeps them tidy. Compare that with privet or Leylandii, which need two or three cuts a year.

The catch is patience. A slow hedge takes a few years longer to fill in. This guide compares the best slow growers for UK gardens, with spacing, planting times and the box problems to know about. If you need height quickly instead, see the guide to fast-growing hedging plants.

What counts as a slow-growing hedge?

A slow-growing hedge puts on roughly 30cm or less a year. That is slow enough to stay neat with one trim.

For comparison, Leylandii can grow 60cm or more a year, and privet and Lonicera nitida grow fast enough to need cutting two or three times. Slow growers spend their energy on dense, compact growth instead. They also tend to live a long time, and a well-kept yew hedge can last for generations.

Most slow hedges are evergreen and fine-textured, which suits a formal edge or a low boundary. For a deciduous or wildlife hedge instead, the native hedgerow species guide has more ideas.

Slow-growing hedges compared

Growth rates below are rough figures for settled plants on reasonable soil. Spacing is for a single row.

Hornbeam is at the faster end, but it is the best choice for a taller hedge on cold, heavy clay.

Yew: the best slow hedge for a formal look

Yew (Taxus baccata) makes the finest formal hedge in the UK. It grows about 20-30cm a year and forms a dense, dark green wall that clips beautifully. One trim a year, in late summer, keeps it crisp.

Yew grows on clay and chalk but hates waterlogged soil. On heavy, wet ground, plant it on a slight ridge or improve drainage first. Unlike most conifers, yew regrows from old bare wood, so an overgrown hedge can be cut back hard and recovers.

Warning: Yew is poisonous to people, dogs, cats, horses and farm animals. Every part is toxic apart from the red flesh round the seed. Never plant it where horses or livestock can reach it, and bag up clippings promptly.

A settled yew hedge holds a crisp face with just one trim a year. Nothing else gives quite such a dense, dark finish.

Holly: the slow hedge for security and wildlife

Holly (Ilex aquifolium) grows about 15-25cm a year and clips well to 1.5-3m. Its spiny leaves make a boundary that few people or animals push through. The dense evergreen cover gives birds shelter and nesting spots.

A berrying holly hedge feeds blackbirds and thrushes through winter. Pick a female variety such as ‘J.C. van Tol’ for berries.

Only female hollies carry berries, and most need a male nearby. ‘J.C. van Tol’ is a self-fertile female variety, so it berries on its own. Holly copes with shade, clay, chalk and coastal wind. It can sulk for a year or two after planting, then grows away steadily. Wear thick gloves for the yearly trim. The guide to growing holly covers varieties and care.

Box: the slowest, but now a risky choice

Box (Buxus sempervirens) is the classic low hedge for edging paths and knot gardens. It grows only 10-15cm a year and copes with sun or shade. Sadly, two problems now make it a gamble in many gardens.

Box blight is a fungal disease that causes brown patches, leaf drop and bare stems, especially in damp, shady spots. Box tree moth caterpillars strip the leaves, often in summer. Both are covered in the guide to box tree moth treatment.

If box has struggled in your area, plant Ilex crenata or another alternative instead. The guide to box hedge alternatives compares the options.

Box blight shows as brown patches, bare stems and a carpet of dropped leaves. Once it takes hold in a hedge, it is very hard to clear.

Other slow and steady hedging plants

Hornbeam (Carpinus betulus) grows a little faster, but it is the best hedge for cold, heavy clay. It isn’t evergreen, but a clipped hedge keeps its dry brown leaves through winter, so it still screens. On free-draining soil, beech does the same job.

Hornbeam isn’t evergreen, but a clipped hedge hangs on to its brown leaves all winter, so it still gives privacy.

Berberis darwinii makes a spiny evergreen hedge with orange flowers in spring and blue-black berries. Ilex crenata suits low hedges where you want the look of box.

Planting a slow-growing hedge

Bare-root plants are the cheapest way to plant a hedge. They are sold from November to March, while dormant. Pot-grown plants cost more but can go in at any time when the soil isn’t frozen or waterlogged.

1. Dig a trench and loosen the soil well. Mark the line with string.
2. Space yew, holly and hornbeam about three per metre. Space box and Ilex crenata about five per metre for low edging.
3. Plant at the same depth as before, using the soil mark on the stem.
4. Firm gently and water well.
5. Mulch along the row to hold in moisture and keep weeds down.

Water through the first two summers in dry spells. New hedges are far more likely to fail from drought than cold. The guide to planting bare-root trees covers soaking roots and heeling in plants if you can’t plant straight away.

A string line keeps bare-root plants straight and evenly spaced. Winter is the time to plant them, while they’re dormant.

Trimming a slow hedge for a thick base

A thick hedge starts with the first few trims. Let a young hedge shoot up untrimmed and it ends up thin and bare at the base.

Trim with a slight slope so the base is wider than the top. Light reaches the bottom and the hedge stays thick right down to the ground.

For deciduous hedges such as hornbeam, cut new plants back by about a third after planting. For yew and holly, leave the leading shoots to grow until the hedge reaches the height you want. Trim the sides lightly each year from the start.

Always cut with a slight batter, so the hedge is wider at the base than the top. This lets light reach the bottom and stops it going bare.

Do the yearly trim from late August into September. Avoid cutting hedges from March to August if you can, because birds nest in them. Damaging or destroying an active nest is an offence at any time, so always check first. The guide to when to cut hedges explains the nesting rules.

Common mistakes with slow-growing hedges

• Planting box where blight is common. If neighbours have lost box, yours is likely to follow. Choose Ilex crenata instead.
• Spacing plants too far apart. Gaps between widely spaced plants may never close.
• Skipping the early trims. A young hedge left to grow tall quickly ends up thin at the base.
• Planting too deep. Burying the stem can cause rot. Plant to the old soil mark.
• Letting new plants dry out. Water through the first two summers, especially yew and holly.

Month-by-month slow hedge calendar

Now you’ve picked your slow hedge, follow the hedge planting guide step by step to get it in the ground, and browse the plants hub for the rest of your garden.

Frequently asked questions

What is the slowest-growing hedge for a UK garden?

Box is the slowest, growing about 10-15cm a year. It makes a dense, fine-leaved evergreen hedge that needs one trim a year. Box blight and box tree moth are now widespread, so Ilex crenata is often the safer choice for the same neat look.

Which slow hedge needs the least trimming?

Yew, holly and box each need just one trim a year. Do it in late summer, once you’ve checked for nesting birds. Faster hedges such as privet and Leylandii usually need two or three cuts a year to stay tidy.

How long does a yew hedge take to grow?

Allow several years for a yew hedge to reach head height. Yew grows about 20-30cm a year once settled. Small bare-root plants take longer than bigger pot-grown ones, but yew is quicker than its reputation suggests.

Is yew poisonous to pets and livestock?

Yes, yew is poisonous to people, dogs, cats, horses and farm animals. Every part is toxic apart from the red flesh round the seed, and the seed inside it is poisonous too. Never plant it where horses or livestock can reach it, and keep clippings away from animals.

What can I plant instead of a box hedge?

Ilex crenata is the closest box alternative for a low, neat hedge. It has small, glossy leaves and clips well. Euonymus japonicus and yew are other good options. The guide to box hedge alternatives compares them in more detail.