There is a right and a wrong way to cut our hedges, according to Teagasc countryside management specialist, Catherine Keena.

And ‘neat and tidy’ are ideas that all of us must rethink when it comes to managing and maintaining not only our hedges, but our ditches, verges, gardens and parks.

Here, as part of Biodiversity Week, we look at the most common hedge types in Ireland and provide some handy hints on how to maintain them.

Common hedges

“There are two types of hedges: topped and un-topped, or ‘escaped hedges’ as I call them,” said Catherine.

“The latter are the tree-lines that we see, they have escaped from the hedge, have never been topped, and should never be topped.

“But, what can sometimes happen is that they are cut to four or five feet high, which pulls the growth up to that level and destroys the hedge forever.

“This is the wrong thing to do.”

In general, Catherine said, these hedges tend to be left alone as they are often boundary hedges within farms.

But, she advised: “On these hedges, you side-trim only, never top them.”

Hedges – flat and short

The flat-topped, straight-sided hedges that are a common around the country during hedge-cutting season, from September 1, to the last day of February, can be greatly improved, and for good reason, according to Catherine.

“These could be 100% improved if they were allowed to grow to 1.5m and an individual thorn tree was allowed to grow up within the hedge.”

Teagasc advises having at least one thorn tree – either whitethorn or blackthorn – in every 300m of hedge.

It can be an existing mature thorn tree, but these are rare in topped hedges, or a new thorn sapling.

Beautiful whitethorn growing in a field. Image source: Teagasc

A thorny subject

“If the hedges are less than 1.5m high, birds won’t nest in them and you won’t have all the associated mammals and insects,” said Catherine.

“If you don’t have the thorn trees then you won’t have flowers for the bees or food for the birds. So, you will have very little life in this kind of hedge.

 “If you chop down that lovely escaped hedge, and pull all the growth up to the cut height, you end up with a toilet-brush hedge – a big stalk at the bottom with a little fringe on top,” said Catherine.

While one thorn tree in 300m may appear low, it is better to allow another new thorn develop in future years, giving a diversity of height and structure with developing thorn trees at different stages rather than all one height, according to Teagasc.

Key criteria for trimmed hedges
At least 1.5m above ground level or top of any hedge bank – for birds to nest and have cover over and under the nest;
contain occasional thorn trees for more flowers for bees, and fruit for birds and small mammals.

Simple message

“These are the simple messages that we need to get out to the general public, to contractors, to farmers, to everyone,” said Catherine.

“Neat and tidy is our problem, but it is not a problem only on farms, it is countrywide across towns and villages where you see everything mown and sprayed.”