Trinity tree of the month- the Kentucky Coffee Tree

Posted on: 01 August 2023

This month we are featuring the Gymnocladus dioicus, commonly known as the Kentucky Coffee Tree, which was planted in 2020 on the boardwalk side of College Park.  It is currently 5.6 metres tall, 25 cm in girth, and can grow to almost five times its current size.  When mature it will store up to 1200 kg of carbon.

The species is native to Ontario, Quebec and the central and Eastern United States, so it tolerates our climate very well. The seeds were originally roasted, producing a coffee like drink.  Like many trees in the Fabacea family, the seeds are toxic, however it is unlikely to produce these in the Irish climate. Native Americans are said to have roasted and then ground the seeds to create a coffee flavour drink.


This tree has dark grey and highly fissured bark and produces very large leaves which at times can stretch up to one metre. When the leaves are shed for winter, you see it has a very open irregular branching pattern, giving it a gaunt look.  The tree can tolerate air pollution and adapts well to urban conditions, making it a suitable city tree.

As the Latin name suggests, this tree is dioecious which means there are separate male and female trees. Both are required to produce the seed pod. The male flowers are smaller than the female, which can be up to 25cm long and are also quite fragrant.  These give way to produce the seed pods, which are flat and brown. Warm summers are required for flowering – one can only hope!  

Thanks to John Parnell, David Hackett and Estates and Facilities for the information, and for keeping our trees in good health and to Stephen Waldren and Michelle Murray for their expertise. 

Media Contact:

Katie Byrne | Public Affairs and Communications | | +353 1 896 4168