Trees offer shelter and a stock-proof barrier as well as boosting biodiversity and providing timber income
I’m lucky that during lockdown I can walk straight out my front door and go for walk up a nice, quiet country lane. On the day I’m writing this, the weather isn’t great, but I was amazed the difference a few roadside trees can make.
Sections along the lane where there are trees in the roadside hedges are so much more sheltered, with less rain and wind. I can now fully appreciate why animals (and crops) enjoy such shelter.
And that is the point my colleague Kevin O’Connell made in a recent video: trees can add so much to farm hedges.
The video was produced at Ballyhaise College in Co Cavan, which is situated on an estate of 220 hectares of grass and woodlands.
They can offer a wide range of land-based courses in agriculture including dairying, sheep, beef, mechanisation, pigs and poultry as well as forestry.
They can build important topics like sustainability, environment, biodiversity and habitat into their training programmes.
This should give the young farmers ideas how to incorporate those important elements into their own farms.
Kevin made the point that it is of critical importance to connect hedgerows with the woodlands on the college farm.
This will provide an ecologically rich network across an intensely farmed landscape, allowing flora and fauna to ‘travel’ from one side to the other.
Wild plants such as bluebells or wood anemones will not be able to spread across a large field.
Or can you imagine a small chaffinch trying to fly across a large field without any protection? I’m sure a hungry sparrowhawk may have other ideas… But where hedgerows are interconnected with woodlands, it provides that all-important landscape interconnectivity.
Growing timber in hedges
It is not only about biodiversity either. While maximising ecological value, you can also grow quality timber with appropriate management within hedgerows.
When Ballyhaise College plant new hedgerows, they add top-quality trees such as wild cherry at the same time.
As the hedge grows up over time, it will provide a stock-proof barrier, shelter and an improved microclimate to animals and crops.
It will also grow top-quality hardwood timber.
Hedgerow trees need intensive and careful management. For instance, when the hedge is being trimmed, tie a large coloured piece of plastic around the trees so that they can be easily seen and avoided.
Hedgerow trees also need regular pruning to produce a long length of straight sawlog and knot-free timber.
Formative shaping and high pruning can be done in summer and winter dependent on the species but must be avoided at all costs during spring and autumn.
Hedgerow and tree function
Also consider carefully the role you wish the hedge to play. Are you looking for a stock-proof barrier, or to maximise biodiversity value or to provide shelter?
Yes, most hedges are multi-purpose but sometimes you may wish to focus on a particular objective.
Roadside hedges for instance — along internal or external roadways — need to be regularly trimmed back to ensure safety of road users.
The same is true for hedges planted close to farm structures, such as sheds, yards, cattle crushes or various types of machinery.
Farm safety comes first — always.
However, where hedges do not obstruct road users or do not overhang the cattle crush, it is a good idea to mix in a wider variety of other hedgerow species such as spindle, guelder rose and hazel.
Management can also be less intensive: allow the hedge and hedgerow trees to grow up taller and broader at the base.
This management and species choice will make the hedge less stock-proof but adds greatly to biodiversity value.
Caring for special trees
Sometimes the focus is on the preservation of special, rare trees that also have great biodiversity value. A good example in Ireland is wych elm.
After a highly lethal and virulent strain of the Dutch elm disease was introduced into Europe in 1967, most elm trees were killed over the next 20 years or so.
It is important to try to preserve our few surviving specimens.
Field corners are often awkward to farm and as a result are under-utilised.
However, they make excellent locations to place small but valuable woodlands. They don’t affect road safety while benefitting the surrounding agricultural land.
It is important to ensure that such small woods are connected into the existing hedgerow network on the farm to maximise environmental (and economic) benefits.
Not all hedges need to be planted. Sometimes, existing farm hedges that are maybe a little worse for wear can be rejuvenated.
A couple of years ago, Ballyhaise College cut back to ground level an old blackthorn hedge, planted up the gaps with a variety of plants such as hazel, guelder rose and spindle.
The hedge was then allowed to regrow for a number of years. It is now managed by breasting it every couple of years to maintain an A-shape — tall and narrow at the top while much broader at the bottom.
This approach maximises shelter, biodiversity value and makes it stock-proof.
Kevin’s conclusion is very clear: “Trees and hedgerows bring many benefits to any farm. Benefits include shelter, biodiversity, improvement in microclimate, carbon sequestration and landscape value.”
Watch this video
If you want to hear principal John Kelly and Kevin O’Connell talk about their approach to tree and hedge management at Ballyhaise College, then watch this video: youtu.be/QxOgwUGEgHA.
www.youtube.com/teagascforestryvideos also has videos on a wide range of forestry-related topics.
Steven Meyen is a Teagasc forestry advisor based in Ballybofey; email@example.com