Hedgerows are increasingly considered to be our most important landscape feature in view of the range of services they provide, and often have been described as the ‘rainforests of Ireland’.

Not only are the aesthetically pleasing on a farm but they provide shelter in poor weather, shade in extreme heat and are now recognised as important carbon sinks as well as increasing on-farm biodiversity.

But all of these roles depend directly on how hedges are managed, highlighted by Hedgerows Ireland at its recent walk on the farm of Pat Maher, a dairy farmer from Cashel, Co Tipperary. While hedgerows can absorb carbon, they can also emit carbon when poorly managed through excessive cutting or removal.

The art of hedge laying

Professional and award-winning hedge layer Richard Markham gave a demonstration on the day of how to lay a hedgerow.

Whitethorn slips had been planted on Pat’s farm eight years ago and had now reached roughly 12ft in height, what Richard described as the perfect height for hedge laying.

Younger or shorter trees could be laid in the case where they are very tightly spaced together, with both methods intended to create a stockproof hedge without any gaps.

Richard demonstrated how to lay a hedge by cutting through the stem part way to allow it to be bent over and ‘laid’.

Excess brash was removed by Richard on one side of the hedge where it ran alongside a farm roadway to allow for ease of access for machinery.

The side of the hedge facing out on to the field (the livestock side) was left mainly intact to fill the hedge. The stem is cut through four-fifths of the way and bent over, with the bend known as a pleach.

“Everywhere I’ve cut, where I’ve made those pleaches, come next March they are all going to start to reshoot. This will happen with hazel, blackthorn, hornbeam and beech.

“What we are basically doing with hedge laying is regenerating the whole hedge. All of those stems are going to reshoot next year.

“You give that hedge 18 months to two years, you’ll have completely new growth at the bottom; it becomes stockproof. These are our old barb-wired fences.’’

Richard then gave a demonstration on supporting the hedge, noting that it may not always be necessary and will depend on budget and hedge purpose.

Timber rods are driven into the ground roughly 3ft apart, with hazel or willow slips plaited together in a rope-like form over the top of the rods, with the supports eventually rotting away as the hedge thickens and becomes more durable.

A-shaped hedges

The second part of the working demonstrations consisted of local contractor Philip Hickey showing how to routinely cut hedges.

Current recommendations are to consider a move from annual cutting to a three- to five-year rotation to allow carbon sequestration, fruiting/flowering, etc, to occur on uncut hedges and to allow gradual increase in height.

Careful cutting on a rotation has increased the height and thickness of hedges on Pat Maher's dairy farm.

Simply put, the goal is taller, wide-based, dense hedgerows, which connect with each other and where trees are allowed to grow at intervals (songbird trees).

Pat has been doing such on his farm over the past number of years, with the evidence to prove it.

The A-shaped hedges have been carefully managed and now stand to a height of approximately 15ft in maturity.

Where trees have been poorly managed through hedge-cutting and appear gapped at the bottom, or “toilet brush-shaped” as Alan Moore of Hedgerows Ireland described, coppicing of trees (cutting down low to the base) to reinvigorate them and the planting of new slips in between older trees may be required.

The stem is cut four-fifths of the way through and bent over, with the all important cambium layer still attached. New shoots will now appear from the base as well in the coming years.

Where hedges have been allowed to mature into tree lines, he strongly advocates that they are left uncut, or side-trimmed only because of the very high nature value of these often ancient field boundaries.

Under threat

Ash dieback has ravaged native Irish ash trees, one of Ireland’s primary hedgerow trees, which was brought in from imported saplings.

The fear that Hedgerows Ireland now has is that fireblight disease is being brought in by the importation of whitethorn whips from countries which are known to have the disease. Fireblight is untreatable and also affects apple and pear trees.

Obligations

The majority of these whitethorn slips have been imported as part of farmers’ obligations under ACRES to plant hedges, with Hedgerows Ireland highlighting the failure by the Department of Agriculture to anticipate the huge demand from farmers for this option in the scheme.

This led to the Department relaxing its ban on non-Irish plants in late November 23 because Irish-grown plants ran out. It is now feared that the importation of close to 1,000,000 slips could greatly increase outbreaks of fireblight.

There were 17 cases confirmed by the Department in Ireland in 2023 alone.

Concern

The removal of hedgerows is an ongoing concern for the group. Even when replaced with new hedging, the replacement hedges take many years to achieve equivalent size and are often a monoculture of whitethorn compared to old hedges which are typically multispecies (much better for wildlife) and have an accompanying ditch which contributes to flood control, according to the group.