Best Practice hedge cutting for our two hedge types

With the opening of the hedge cutting season on 1 September, best practice hedge cutting is more important than ever because of the role of hedges in biodiversity and carbon and the need to improve their condition. Catherine Keena, Teagasc Countryside Management Specialist has more in Hedgerow Week

With contractors employed to cut the majority of hedges in Ireland, having a conversation with the hedge cutting contractors is essential to communicate what is needed.

Photo above: At the Hedge cutting event in Gurteen College - Ger Hanrahan contractor, Caroline McGeogh lecturer Gurteen College, Martin Tuohy contractor, Francis Quigley Teagasc machinery specialist, Ann Hanrahan contractor and Catherine Keena Teagasc countryside management specialist

The key message is that there are two types of hedges based on structure, each with different biodiversity values and management requirements.

Failure to distinguish between the two types can lead to confusion and inappropriate management.

Teagasc recommendation is that every farm should have some Escaped hedges and some Topped hedges.

Escaped hedges

Photo above: Escaped hawthorn hedge in flower

Firstly, Escaped hedges (Treeline / Linear woodland) which have never been topped, have high biodiversity value in the canopy, while thin at the base.

Best practice management of Escaped hedges is to side trim only and never top.

Topped hedges

Photo above: Topped hedge side trimmed from a wide base to a triangular profile

Secondly, Topped hedges have high biodiversity value in the dense base for nesting birds and cover for small mammals and can also have some of the canopy biodiversity when occasional thorn saplings are allowed grow up and mature as flowering and fruiting thorn trees.

Best practice management for Topped hedges is to side trim from a wide base to a triangular profile leaving as high as possible while still possible for the flail to to the peak to control apical dominance, but at least 1.5 m above ground level or top of bank (if present).

Retain occasional thorn saplings to mature as standard thorn trees with a full canopy within every topped hedges.

Little and often trimming is better for hedges.

Where best practice hedgerow management is followed on a farm, flowers and fruit are available on Escaped hedges and on the thorn trees retained within Topped hedges.

‘upside down toilet brush’ hedges

Photo above: ‘upside down toilet brush’ hedge being coppiced

Topped hedges without a dense base have come about as a result of Escaped hedges cut down to a height of 1-1.5 m at some stage in the past. These are now ‘upside down toilet brush’ hedges and it is impossible to trim to a triangular profile. They are currently of low value for biodiversity and carbon. These are ideal candidates for coppicing under ACRES, in order to renew the base.

Where such hedges have a whitethorn stump every metre or so, there is great potential to improve their structure for biodiversity and carbon by coppicing. This involves cutting at ground level with a clean sloping cut so rain will run off.

Photo above: Hegerow coppicing

Hedgerow Week 2022

Friday August 26th to Friday September 2nd marks Hedgerow Week 2022.
The theme for the week is Best Practice Hedge Cutting
Get more information on hedgerow week 2022 here
Get more information on hedges here