If a yew has been left untrimmed, or has been badly clipped in the past, then thick, long stems can start to grow up on the outside of the hedge. These will thicken over time, causing the hedge to bulge and sag.
Improve Yew Hedges Appearance
A yew should have short green, lateral growth on the outside. The thicker stems are the inside, creating a strong framework for the hedge.
The soft, lateral growth on the face of the hedge responds well to regular clipping, creating a tight, dense appearance.
How to remove the vertical stems
Cut just above a point where there is young growth sprouting from the stem. This point should be set back slightly from the outer surface of the hedge.
But it has left a hole?
Don’t be too concerned. The hole will soon fill in as the young, horizontal growth thickens. Regular tip pruning will encourage this young growth to thicken faster.
Continue to remove vertical stems
Clipping with a hedge trimmer may still leave some vertical growth. Remember to remove these small, part-cut stems before they become a problem. Snip them off with sharp secateurs at a point that is set back slightly from the outside surface of the hedge.
Can take a bit of time snipping back the verticals but it’s worth it to promote the soft lateral growth.
When and how often should a yew be clipped?
Clip a yew hedge at least once a year. The best time is between August and early December.
The process of removing vertical growth from the outside will become less of a requirement as the hedge matures.