Anja Murray: Neat and tidy isn't always best when it comes to hedgerows

Anja Murray: "Considering that one-third of native bee species in Ireland are now threatened with extinction here, allowing hedgerows to flower wherever possible is a basic offering for their needs. Hedges in flower begin with blackthorn and willow catkins in February and March; followed by rowan and hawthorn blossom in May; and crab apple, elder, and dog rose in June. Undisturbed banks and verges also provide nesting opportunities for many wild bee species and other declining invertebrates."

As a nation, we love our hedgerows almost as much as we love spuds. Like with potatoes, we never seem to bore of the topic of hedges, whether it's celebrating the may blossom at the start of summer; the bounty of hedgerow fruits as Autumn unfolds; or the upset caused by badly flailed roadside hedges. Just as everyone has their own take on what constitutes the best kind of potato or the best way to cook them, hedges come in all shapes and sizes and there are many ways to manage a hedge, or not. Personal preference differs — although for wildlife, some hedges are definitely better than others.

Old townland boundary hedges, many of which have been around since medieval times, are some of the most species-rich hedges, in addition to being of historical significance in the landscape. It's easy enough to ‘get your eye in’ and learn to recognise a townland boundary hedge, as they tend to have especially large banks, sometimes beautifully constructed with stone facing. The drainage ditches running alongside the banks are generally dug deep.

Also, because these hedges have been around for several hundred years, natural processes have had time to endow them with a great variety of wild tree and shrub species. Depending on soil type, its normal to see wild sown trees, shrubs and climbers such as such as hazel, crab apple, wild cherry, spindle, dog rose and honeysuckle growing well in townland boundary or other especially ancient hedges. Guelder rose, for example, stands out now with its russet-coloured leaves and clusters of super shiny round red berries, as does spindle with its vivid autumn colours.

Each of these wild species have found their way via the birds and small mammals who eat the fruits and inadvertently transport seeds in their droppings. Generally speaking, a greater diversity of tree and shrub species means better resources and opportunities for wild creatures, from the bees, shield bugs, hoverflies and butterflies up to the hedge sparrows, warblers and kestrels who depend on healthy hedges.

Anja Murray: "Excessive trimming of hedgerows is problematic in many parts of the country, though neglect can be just as damaging in the long run. For all that we love our hedges, there’s a great deal of room for improvement in how well we could be managing them."

Enclosures Act hedges were laid down as part of land subdivision in the 18th and 19th centuries and were often planted without much of a bank or a ditch and with just one or two shrub species. Across England, Wales, and Ireland, there was great resistance to common land being parcelled up into hedge-bound fields by landlords, exacerbating inequality and denying access to many. However, the network of hedges through otherwise treeless landscapes has left us with a valuable resource today, for heritage, aesthetics and wildlife. Most of these Enclosures Act hedges now contain much more than the hawthorns they were initially planted up with: holly, willow, elder, rowan, and elm, among others, having found their way in over time.

As well as history, management makes a significant difference to the quality of each hedge. Some folks prefer a neat and tidy hedge, trimming tightly and often and keeping the over profile low. Others like to let the hedges grow a bit tall, offering better shelter to farm animals and wildlife alike. Taller and bulkier hedges that aren’t trimmed more frequently than every six years provide more flowers and fruits than hedges that are trimmed each year, as it takes about four or five years for cut stems to be able to flower and set fruit again. Too much trimming leaves a hedge that won’t do much for pollinators, nesting birds, or landscape.

Considering that one-third of native bee species in Ireland are now threatened with extinction here, allowing hedgerows to flower wherever possible is a basic offering for their needs. Hedges in flower begin with blackthorn and willow catkins in February and March; followed by rowan and hawthorn blossom in May; and crab apple, elder, and dog rose in June. Undisturbed banks and verges also provide nesting opportunities for many wild bee species and other declining invertebrates.

Now that the bird nesting season is over, contractors are out with flails all across the country, trimming back roadside hedges in earnest. On roadsides, light side trimming is generally required on an annual basis... though there’s a big difference between good trimming and bad.

A good clean cut with sharp blades tends not to be damaging to a hedge. Occasional trimming helps keep a hedge in shape and supports the wildlife value of many hedges. As with pruning in the garden, each stem that is cut responds by sending out new, vigorous side shoots, especially in the case of hawthorn, blackthorn, and holly. This response is what thickens up a hedge, as these thorny species have evolved to respond to browsing animals by becoming even thornier and spikier. Thick growth at the base, up to 1.5 metres, is where many of the songbirds who nest in hedges chose to build their nests, as it is the impenetrable lower and middle sections of a hedge that offer the best protection from predatory crows, kestrels, and foxes.

Hedgerows absolutely obliterated on road to Ballynamona Strand, Cork. I was only admiring it this week. I confronted the farmer (politely), & he smiled ‘road safety’. You can see below there was no road safety issue. The danger on our roads is people driving like lunatics. 1/2 pic.twitter.com/TPoobW8xvf

— Irish Wildlife Sounds (Seán Ronayne) (@SoundsIrish) August 18, 2024

Bad trimming, on the other hand, can have the opposite effect. For convenience and cost-effectiveness, trimming is mostly carried out with flails. Trimming without skill and due care can cause stress to woody shrubs and trees, weakening them over time and causing a lot more rot and disease than would otherwise occur. Blunt bladed flails, for example, shred rather than cut through woody branches, leaving exposed damp crevices where fungal and other diseases set in.

Each hedge is different, a product of its history, species composition and management. And as a living entity, a hedge is dynamic, constantly growing and always changing. What kind of management is best for the functionality and wildlife value will be different for each hedge too. Some only need a gentle side trim; others will benefit from a more dramatic overhaul via hedge laying or coppicing. Excessive trimming is problematic in many parts of the country, though neglect can be just as damaging in the long run. Learning to ‘read’ each hedge and determine the best management choices accordingly is something that we, as a nation, could start to take more seriously. For all that we love our hedges, there’s a great deal of room for improvement in how well we could be managing them.