Huntingdon Castle

In the grounds is a Yew Walk, once considered to be 600-years old and a survivor from the days of the monastery. Even the 1680 planting date given in the Tree Register of Ireland notes would mean that these trees have grown very slowly. It is known that yews that are managed (those at Painswick in Gloucestershire being a classic example) are small girthed for their age. Is it possible that these were subjected to topiary in their early years? The height of the trees is given as 14m, and a girth of 3m.