Teagasc: how to maintain the value of your hedgerows

ALMOST every farm in Ireland has hedgerow which gives the landscape its distinctive character and field pattern. Hedgerows have many values and functions including flood control, in which the root systems of hedgerows regulate water movement and help prevent flooding.

Hedgerows have become very important wildlife habitats in the countryside, providing food, shelter, corridors of movement, nest and hibernation sites for many of our native flora and fauna. Mature trees provide roosts for bats, while saplings are important perching posts for birds. 35 species of bird nest in hedgerows, and hedgerows with a dense base provide cover for small birds and mammals, such as the hedgehog and field mouse.

A wide variety of plants can be found in hedgerows which provide food sources. Hedgerows are part of Ireland’s cultural, historical and archaeological heritage and provide a boundary between townlands and farms.

Understanding the value of hedgerows and their importance to farming and the environment means an appropriate management plan should be drawn up for all hedgerow on the farm. Hedgerows cannot be trimmed between March 1 and August 31 each year.

Different types of hedgerow will require different management. Hedgerows with a dense base should be trimmed from a wide base with sloping sides to a triangular shape, leaving mature trees and new saplings at irregular intervals.

Hedgerows which have grown high and lost their dense base can be allowed to grow into relict hedgerows, or rejuvenated by laying or coppicing. Hedgerows where mature trees have grown with a full canopy and other sections of hedgerow which have died, leaving gaps in the hedgerow, should be fenced off from stock and left alone, as they provide food and shelter for birds and bats.

Whitethorn trees that grow up and mature within hedgerows provide spectacular displays of white blossom in late May, and haws in Autumn.

The lifespan of hedgerows can be extended by rejuvenation. Rejuvenation should be carried out between September 1 and end of February by either coppicing, laying or planting new hedgerow. In laying hedgerow, stems more flexible in autumn are practically cut through near the ground and bent over or laid to form a living barrier which continues to grow. The new growth comes from the cut stump at ground level and from the laid stem. The laid hedgerow must be secured against strong wind and livestock rubbing. Coppicing is less time consuming and involves the stems being completely cut through close to the ground, encouraging new growth at this level.

If a farmer intends to restructure their farm by the removal of field boundaries, screening is required by the Department of Agriculture if over five hectares are affected or over 500 metres of field boundary is being removed. Screening is also required if the proposed works are to be carried out within a proposed NHA or a Nature Reserve.

Hedgerows are included in the calculation of Ecological Focus Areas greening requirement under the Basic Payment Scheme if farmers have more than 15 hectares of eligible arable land.

Hedgerows and ditches are designated as landscape features under the Good Agricultural and Environmental Condition of Cross Compliance. This means that, in general, they cannot be removed. Where in exceptional circumstances a hedgerow must be removed as, for example, to facilitate a farmyard expansion, a replacement hedge of similar length must be planted at a suitable location on the holding in advance of the removal of the existing hedgerow.

The main hedgerow species include whitethorn, blackthorn, holly, spindle, guelder rose and hazel. The best time to plant hedgerow is from October to March, with autumn the best time in the free draining ground and spring in heavy soil. The management and rejuvenation of hedgerows improves wildlife, shelter and scenic appearance, while continuing to farm efficiently.