Getting Hedgerows Fit for Birds and Bees
Mary Roache, ASSAP Advisor, Teagasc Westport asks What is in a hedge? And she looks for the answers in getting hedgerows fit for bids and bees. Mary shares some key points for keeping a hedge in good shape, lists the benefits and the hedgerow management options open to derogation farmers this year
What is in a hedge?
Let’s start at the top. Three large native Irish trees are frequently found in hedges. Oak, ash and willow provide a habitat for numerous invertebrates as well as birds such as the two Irish owls- barn owl and long-eared owl. Whether you like it or not, ivy is a plant of immense biodiversity value which provides nest sites for bats and birds. Its flowers in September/October are the only source of pollen and nectar to bees and hoverflies at this late time of year. Ivy’s late ripening berries still available in January and February may be the only source of food when all else is gone.
Moving down to the body of the hedge, the most predominant shrub in our native Irish hedges is whitethorn (hawthorn) with white flowers amid green leaves in late May and producing red haws in Autumn. Thorn hedges may also include blackthorn which has white flowers on black leafless branches in late March followed by dark coloured sloes in Autumn. Deep within these thorny hedges is a safe nesting area for songbirds such as blackbirds and thrushes. Of the 110 bird species regularly recorded during the breeding season in Ireland 55 use hedgerows. Of these, 35 species nest in the hedgerows which provide cover from overhead and ground predators. The presence of holly, honeysuckle or woodbine and flowering climbers such as bramble or blackberry are a valuable food source for bees and fruits for birds and mammals.
The dense base of the hedge is home to small birds such as robin and mammals including hedgehogs and shrew. In hard weather this may be the only unfrozen foraging ground available. Woodland plants such as primrose, cowslips, ferns and foxglove adorn the hedge base and are a great source of food for pollinators. Currently 1/3 of our bee species are threatened with extinction due to lack of food, flowers and safe nesting sites.
The season for hedge-cutting opened on September 1st and will remain in place until its close on March 1st next year. Although now it is permitted to cut hedgerows please remember that Autumn is an important time for wildlife as they build their stores for the winter. Hedgerows at this time of year are heaving with fruits, nuts, berries and so if possible and also safe to do so it’s better to hold off with cutting until later in the season.
Key Points for good hedges
- At least 1.5m above ground level, the taller the better
- Dense base
- Allow occasional tree/thorn tree to grow up and mature with full canopy
- Mix of different native flora
- Triangular shaped profile to allow light in the base
- Keep pesticides well back and never band spray along a hedgerow
From 1st January 2020 derogation farmers (above 170kgN/Ha stocking rate) must choose to
- Leave at least one mature Whitethorn or Blackthorn tree in every 300m of hedgerow OR
- Maintain hedges on at least a three year cycle to encourage flowering and fruiting
Hedgerows provide food, shelter, nesting sites, habitat corridors and can be also used for flood defences. Strategic planting can be used on farms to prevent the run-off of soil and sediment and also to intercept and take up nutrients and help improve water quality. With over 689,000km of hedgerows in Ireland their future role in carbon sequestration will also be vitally important.