How to Close Hedge Gaps With a Simple Pruning Trick

A hedge with bare patches immediately looks neglected and see-through.

A simple, almost free trick can often close these gaps within just a few weeks.

When a hole appears in a hedge, many amateur gardeners instinctively reach for their wallet. Yet in many cases, the issue can be solved using the plants already there. What matters is close inspection, a purposeful pruning technique and a little patience – rather than continually buying replacement shrubs.

Why new shrubs often do not save a hedge

On spotting a gap in their hedge, most people head straight to the garden centre. It seems logical: something is missing, so another plant should be put in. In reality, this approach is often disappointing.

A young shrub suddenly has to compete with long-established, vigorous neighbours. The older plants deprive it of light, water and space. The newcomer struggles, grows more slowly and often remains smaller than the rest of the hedge for years.

What appears to be a missing section is not always genuinely empty, either. The hedge may simply have lost its shape, become weakened or gone bare internally. Adding new plants does little in these cases, because the underlying cause remains.

“Before spending money on new hedge plants, check whether the existing shrubs can produce new growth again with the right pruning.”

Look closely: is the hedge really dead, or simply tired?

Before reaching for a spade and your wallet, carry out a brief inspection. Many branches that seem dead are still alive.

The fingernail test

A straightforward check is enough: lightly scratch the bark with your fingernail or a clean knife.

• If the tissue beneath is green and moist, the shoot is still alive.
• If it is brown and dry, that branch has genuinely died.

Living but weak branches can be encouraged back into growth. Older hedges in particular often contain long, bare shoots that carry leaves only at their tips. With appropriate pruning, these can shoot again and fill the gaps.

The effect of light and air

Hedges planted very closely together or kept permanently in shade become bare inside more quickly. Outer shoots shade the base, causing the plants to lose leaves and needles there. From the outside, this can look like a hole, when the real problem is a lack of light and air within the hedge.

In these situations, considered thinning is more effective than adding another shrub. Removing selected branches and preventing the hedge from becoming too wide allows light to reach lower areas, encouraging the plants to grow back more densely.

The pruning trick that closes hedge gaps in weeks

The key is often right beside the gap: pruning the neighbouring shoots correctly. This effectively prompts hedge plants to develop new side shoots, allowing them to grow into the empty area.

How to prune correctly

All you need is a sharp, clean pair of garden secateurs. Work carefully rather than quickly – a few well-placed cuts are enough.

• Shorten the affected branches around the gap by roughly one third.
• Make an angled cut just above a bud.
• Where possible, choose a bud pointing towards the gap.

This method directs growth deliberately: the plant can no longer simply extend upwards, so it responds by producing more side shoots. The hedge becomes denser instead of merely taller.

“Targeted pruning limits height and encourages width – so the hedge grows into the gap rather than past it.”

The best time for a “restart”

Early spring is ideal, as sap begins to rise and plants are close to producing new growth. Hedges usually respond then with fresh green shoots within a few weeks.

Pruning in late summer can also work, although there is less time for fresh growth before winter. In all cases, substantial pruning should be carried out in frost-free weather so that the shoots are not damaged by frost.

When a new shrub is still worthwhile

Sometimes even the best pruning will no longer help: if entire plants have died completely or there is severe frost damage, replacement is difficult to avoid.

Choose the right variety

If you are replanting, be consistent. The new plant should be the same species as the rest of the hedge. Different varieties often grow to different heights and widths, and at different speeds. This creates an uneven overall appearance and makes every maintenance trim more difficult.

Allow enough space

New shrubs should not be squeezed directly into the old root system. Leaving some space is essential for their development.

• Depending on growth vigour, leave 40 to 60 centimetres between the new plant and the nearest established shrub.
• Dig a sufficiently large planting hole and loosen the soil.
• Spread the roots carefully, avoid planting too deeply and water in thoroughly.

This gives the young shrub the chance to establish its own roots, rather than competing permanently with older plants for every drop of water.

Water and mulch: the overlooked helpers

Whether you prune hard or plant anew, success will not come without water. Care in the following weeks determines how well the hedge progresses.

Water properly rather than “a little every day”

Many gardeners water too frequently but too lightly. It is better to water thoroughly at longer intervals. This lets moisture penetrate further down and encourages roots to grow deeper too.

• Water regularly for 4 to 6 weeks after pruning or planting.
• Water deeply once or twice a week, according to the weather.
• Avoid waterlogging – the soil should be moist, not wet.

Mulch as a protective layer

A 5 to 8 centimetre layer of organic material at the base of the hedge acts like a protective covering. Suitable materials include:

• chipped branches or pieces of bark
• dried grass clippings
• shredded autumn leaves
• straw or other plant material

Mulch keeps the soil moist for longer, suppresses weeds and gradually breaks down into valuable humus. However, do not pile the material directly against the stems, as this can cause mould.

How to keep your hedge dense for the long term

Once the gap has closed, the ongoing task begins: maintaining the hedge so that new holes do not develop in the first place.

Five simple maintenance habits

• trim lightly once or twice a year rather than cutting back severely only rarely
• water purposefully for several weeks after heavier pruning
• renew the mulch layer in spring when needed
• remove weeds regularly at the base so they do not compete for water
• monitor weak or thin areas early and shorten them selectively

These measures keep the hedge denser, make it look better maintained and provide improved privacy and wind protection. A dense green barrier also reduces noise and creates a more sheltered garden environment.

Practical examples and useful advice for hedge owners

With fast-growing species such as privet or hornbeam, a confident spring pruning is often enough to close large gaps. Thuja and yew respond more slowly, but with suitable care they too can produce fresh green growth around the edges of a gap.

If you are unsure how much can be removed, proceed gradually: it is better to prune in two stages than to cut too deeply in one go. After each trim, inspect the hedge: if light can reach the stems again, there is a good chance that new shoots will grow from the interior.

The real risk comes from cutting radically and completely into old, brown wood. Many conifers will not regrow from it. Before pruning, always check that green sections containing buds are still present.

Following these steps not only saves money on replacement plants. The hedge will develop more robustly because it can thicken up under its own steam. Particularly during dry summers, a sturdily established, well-maintained hedge proves its worth – it stays green for longer, protects the garden more effectively and has a more uniform appearance.