Do you want a hedge with a dense base that will require regular topping, or a line of trees that won’t ever need to be topped? Both require very different management, and inappropriate management of either one will result in damage to the hedge and biodiversity.

  • Escaped hedges: escaped hedges have an untopped hedge or treeline and do not require topping. Only the sides should be trimmed.
  • Topped hedges: these are maintained as hedges, each a little above the previous year’s cut. The aim should be to grow them up to at least 1.8m and retain a new thorn tree in every hedge.
  • It is important to understand how trees and shrubs grow in order to grow a hedge successfully. The central shoot of the tree grows up, causing the tree to develop into a single-bole stem with a canopy. This occurs as a result of apical dominance, which is when the main stem of the plant is dominant over the side stems.

    When apical dominance is disturbed by pruning, lateral and dormant buds just below the cut fight to become the new terminal leader. Farmers need to bear in mind that hedges are managed habitats and need management to be maintained.

    Native species

    Farmers should plant species of native Irish provenance, meaning that the plants were grown in Ireland from seed collected from Irish trees.

    Native Irish species are in tune with each other, with the timing of flowering suiting associated dependent species. Using native provenance hedging stock is also better for biodiversity as it reduces the health risk to our native trees and hedges.

    What species to plant?

    Trees and shrubs that tolerate trimming should be chosen such as the thorn species – whitethorn, blackthorn and holly. These are excellent for the structure in hedges and should provide the basis for all farm hedges.

    Such species are the only ones recommended to take up the majority of species in topped hedges as they are also ideal to provide the occasional mature tree within the hedge without shading out and causing gaps as is common with larger hedgerow trees.

    For a topped hedge, farmers should buy two-year-old bare-rooted whips, six plants per metre, which should be mainly whitethorn. However, once every 2m, replace one with another hedging species that tolerates trimming such as blackthorn, holly, hazel, spindle, guelder rose, dog rose and woodbine. Therefore, for every 100m of a new hedge, you need 550 whitethorn and 50 other species.

  • Firstly, mark out the line of where the new hedge will go using wire, twine or lime.
  • Cultivate the ground using a digger which will make it easier to plant.

  • To protect roots from drying out during planting, it is recommended to keep the plants in the bag until they are needed.
  • Plant in a double-staggered row – with 330mm (just over one foot) between the rows and the same between the plants within the rows – often the length of a boot.
  • Do not bury the stem or expose the roots when planting.
  • Identify some whitethorn, about five per 100m, to be retained as trees and protect these with tree guards.
  • Prune all other plants except holly down to an inch or so above ground level with a sloping cut to leave a sharp point.
  • Put a 4ft- or 1m-wide strip of compostable film or used silage plastic down neatly over the cut stumps, pressing the edges of the plastic into the ground to hold it down.
  • Martin Crowe, Carrigmore, Doon, Co. Limerick.

    From the Footprint Farms

    Martin Crowe, pictured, planted a hedge last Christmas, and plans to continue to do this over the next few years. With the help of his kids over the holidays, Martin put in 350m of a hedge that was made up of mostly whitethorn, dog rose, guelder rose, blackthorn and hazel. The hedge was pruned near the end of March. Martin has now identified a further 750m of an area that he plans to put a hedge along over the next two winters.