Close Hedge Gaps With a Simple Pruning Trick

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

A straightforward, almost cost-free method can often fill 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 instances, the issue can be resolved using the plants already there. Rather than buying more shrubs, it takes a close inspection, a purposeful pruning technique and a little patience.

Why new shrubs often do not save a hedge

On spotting a gap in the hedge, the usual response is to head straight to the garden centre. It seems sensible: something is missing, so another plant should be added. In reality, this approach often proves disappointing.

A young shrub is suddenly placed between mature, well-established plants. Its older neighbours deprive it of light, water and room to grow. The newcomer struggles, develops more slowly and can remain noticeably smaller than the rest of the hedge for years.

Moreover, the apparent “missing area” is not necessarily empty at all. Often, the hedge has simply lost its shape, become weakened or gone bare inside. New plants do little in these circumstances, because the underlying cause has not been addressed.

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

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

Before reaching for a spade or your wallet, carry out a brief inspection. Numerous branches that look dead are still alive.

The fingernail test for living growth

One simple check is enough: gently 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 suitable pruning, these can sprout again and help fill the gaps.

The effect of light and air

Hedges planted very densely or kept in permanent shade become bare in the centre more quickly. Outer shoots shade the base, causing 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 cases, considered thinning is more effective than adding another shrub. Removing selected branches and preventing the hedge from becoming too wide allows light to reach the lower sections, encouraging denser new growth.

The pruning trick that closes hedge gaps in a few weeks

The key is often immediately beside the gap: correctly cutting back the neighbouring shoots. This effectively prompts hedge plants to form new side shoots, allowing them to grow into the empty space.

How to prune correctly

All you need is a sharp, clean pair of secateurs. Work carefully rather than rushing; a few well-placed cuts are sufficient.

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

This method deliberately directs the plant’s growth. Unable to continue growing only in length, it responds by producing more side shoots. The hedge becomes thicker instead of merely taller.

“Targeted pruning restricts 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, when sap is rising and plants are close to producing new growth. Hedges generally respond then with fresh green shoots within a few weeks.

Pruning in late summer can work too, although there is less time for new growth before winter. Any very heavy pruning should always be carried out in frost-free conditions, so the shoots are not damaged by frost.

When planting a new shrub is still worthwhile

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

Choosing the right variety

If you replant, remain consistent. The replacement should be the same species as the rest of the hedge. Different varieties often grow to different heights and widths, and at different rates. This produces an uneven overall appearance and makes every maintenance cut more difficult.

Leave enough space

New shrubs should not be squeezed directly into the old root network. Allowing some distance gives them the room they need to establish.

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

This enables the young shrub to develop its own roots instead of constantly competing with the established plants for every drop of water.

Water and mulch: the overlooked helpers

Whether you have pruned heavily or planted afresh, success depends on water. Care in the following weeks determines how well the hedge recovers.

Water thoroughly rather than “a little every day”

Many gardeners water too often but only at the surface. It is more beneficial to water deeply at longer intervals. This allows moisture to penetrate further down and encourages roots to grow deeper as well.

• 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 saturated.

Mulch as a protective layer

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

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

Mulch keeps the soil moist for longer, suppresses weeds and gradually breaks down into valuable humus. Do not press it directly against the stems, however, 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 fresh 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 occasionally
• water purposefully for several weeks after heavier pruning
• renew the mulch layer in spring when necessary
• remove weeds regularly at the base to prevent competition for water
• monitor weak or sparse areas early and shorten them selectively

This keeps the hedge denser, tidier-looking and more effective as a screen from views and wind. A dense green barrier also muffles noise and creates a more sheltered garden environment.

Practical examples and useful guidance 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 appropriate care they too can produce fresh green growth around the edges of a gap.

If you are unsure how much can safely be cut back, take a gradual approach: it is better to prune in two stages than to cut too deeply in one go. After each cut, look inside the hedge: if light can reach the stems again, there is a good chance that new shoots will grow from within.

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

Following these steps does not merely save money on new plants. The hedge becomes more resilient because it can thicken up under its own power. Especially during dry summers, a robust, well-maintained hedge pays off: it remains green for longer, protects the garden more effectively and has a visually uniform appearance.