Hi – please see attached picture of yews. I live in Oakville and although we had a long winter, it hadn’t been a really cold winter. My front yard has southern exposure so the sun is always facing the yews. I planted them about 4-5 years ago and they have never been like this after a winter season. I cant figure out why they developed only some patchy brown spots – if it was too cold or maybe not enough water before winter – why would only some of the spots be brown this time? As additional info, I did give them a significant prune in July-August 2017 last year which would have been the first time they were given a significant trim – but again not sure why its only spotty brown patches.
Thanks again for your help.
Thank you for contacting the Toronto Master Gardeners with your query.
I applaud you on your neatly trimmed yew hedge. There are many reasons why yews are constantly selected as hedging material. They are easily grown in average, medium moist, well-drained soil in full sun to part shade.
From your photograph it appears that your yews could be suffering from environmental stresses such as wind damage/sun scorch or improper pruning. Fear not, with a little TLC your yews should rebound and thicken up nicely.
Firstly, yews appreciate good soil and will benefit from a yearly application of organic compost. Remember- Nothing kills a yew faster than wet, poorly drained soil.
Yews are most susceptible to winter wind and sun burn and as a result are best sited in an area that is protected from the cold winter winds which we did experience this winter. Begin by giving the yews a good shake to remove the dead needles. The brown areas need to be removed. Sharp, clean pruning secateurs can easily nip off the dead branches – just cut at a junction below the dead branch. Next winter you can try protecting your yews from prevailing winds with physical burlap barriers. Because evergreens retain their needles it is extremely important to water your evergreens right up until freezing.
If you need to shape the shrubs or shorten them, now is a good time. Yews should be pruned in late March or early April before new growth begins. Light pruning may also be done in late June or early July. Avoid pruning evergreen shrubs in the fall. Fall pruned evergreens are more susceptible to winter injury. This link from Iowa State University gives good information on the proper time to prune.
Lastly, a soluble fertilizer for evergreen shrubs and trees can be applied at this time, make sure to follow directions on the package with regards to concentration.
With proper pruning and fertilizing your yews should bounce back nicely.