Finished a project last week reshaping an avenue of Irish Yew. The yews had grown too large and were starting to dominate the space. The original plan was to undertake a major renovation by cutting the yews back to a solid framework of branches. This would have reduced the size of the yews but is a long term solution as they would have taken at least five years to recover. Also many of the yews were missing their central stems after previous renovations so cutting back to a framework would have been difficult. So instead it was decided to give them a hard trim and reshape.
I cut them back to a traditional shape. Their height was reduced to create a flat top and the sides straightened. I also removed some of the vertical growth to reduce the risk of the Irish yews splaying outwards, which is a common problem with this plant. The hard cutting has created some woody patches that will green over within a year or two.
Thankfully these yews didn’t require wiring. It’s a topiary technique that I’m not a big fan of and try to avoid if I can. The practice involves winding a wire around the outside of the yew to hold together all the vertical growth. A tip is rather than wiring around the outside, tie the vertical in from the inside of the plant. This avoids cutting the wire and damaging your blades when trimming up the outside of the yew each year.
From experience I’ve found the traditional shape of flat tops and straight sides is the best for encouraging strong, vertical growth. The choice of topiary designs is very limited for Irish yew because of their ‘fastigiate’ growth habit. But if topiary columns are required then this plant can work well. Just remember to keep the yews regularly trimmed by running the hedge trimmer up the sides and across the tops at least once a year, otherwise the yews can soon start to splay.