Gymnocladus dioica - Growing Guide

Kentucky coffee tree

At Caerhays we have had occasional success in flowering Gymnocladus dioica following a hot dry summer but it prefers much hotter drier conditions than we can give it in Cornwall.

Nevertheless it is an attractive spreading tree with an interesting bark formation that is well worth growing in a hot sunny location. This tree is however dioecious in that you need male and female trees to be growing close by to produce fruit. It would seem, from the large size of the flower panicles, that our tree is a female but, at present, no consort is available.

As its common name implies this deciduous tree originates from central and eastern North America where it grows in woodland. The young twigs have a whitish bloom and the pinnate leaves can be up to 2ft long (with us) with each leaflet divided into eight to fourteen soft hairy leaflets. The leaves turn a superb golden yellow in autumn.

The flowers appear in large panicles of small star-shaped, greenish-white or white flowers. In females the panicles are up to 12in in length but smaller in male forms. Seen from below when the tree is mature these are quite a sight.

The seeds are apparently toxic on this completely hardy tree but this is not going to trouble any of us as things stand today here.
 

• GYMNOCLADUS dioica