The Tree Register of Ireland.

  • Mark Twomey Forest Service, Johnstown Castle, Co. Wexford, Ireland.
  • Aubrey Fennell Thornville, Palatine, Co. Carlow, Ireland.
  • Frances McHugh Teagasc, Coolruss, Tinahely, Co. Wicklow, Ireland.
Keywords: Differential global positioning system, champion trees, Tree Register of Ireland, TROI, Tree Register of the British Isles, TROBI.


The Tree Council of Ireland and The Irish Tree Society initiated the Tree Register ofIreland (TROI) project in 1999 with the aim of compiling a database of trees in Ireland. Five thousand two hundred trees were measured and recorded over the period 1999 to 2001. Of these some 3000 had previously been recorded by Alan Mitchell on behalf of the Tree Register of the British Isles (TROBI). Mitchell covered many of the large estates, public parks and gardens throughout Ireland. Many of Ireland's finest trees however, are found on private farmland and in gardens. TROI endeavoured to both update the tree measurements taken by Mitchell, and to locate and record new trees which were growing in less conspicuous locations. The tallest tree measured was a Douglas fir at Powerscourt, Co. Wicklow standing at 57.5 m. The largest girth tree was a Monterey cypress at Killyleigh, Co. Down, measuring 12.09 m. The oldest tree recorded was a yew in Co Wexford, which was estimated to be between 800 and 1200 years old. Differential Global Positioning System (DGPS) technology was used to accurately determine tree location and to facilitate subsequent relocation. The Tree Register can be viewed at the National Botanic Gardens at Glasnevin, Dublin and provides the most comprehensive database of outstanding tree specimens in Ireland.
How to Cite
Twomey, M., Fennell, A. and McHugh, F. (2002) “The Tree Register of Ireland.”, Irish Forestry. Available at: (Accessed: 30September2023).