Trimming an evergreen hedge

Asked March 12, 2016, 4:14 PM EST

I have a hedge I would like to trim. It has brown spots, holes and woody interior. If the hedge is trimmed down a foot or two, would that help to fill the woody interior and holes or make it worse? If trimmed, would it be worse? FYI, I live in West Linn, OR.

Clackamas County Oregon

1 Response

When pruning conifer hedges, it is VERY important not to cut beyond the point on any branch where healthy green foliage starts. If you cut conifers back to bare wood, they do not generate new green growth (unlike many deciduous or broadleaf hedges). The branch without healthy green needles will die, and the result will be a hole in the hedge. The damage will not necessarily damage the health of the plant (if you left enough green foliage elsewhere), but it will be unsightly, and basically permanent.The only fix at that point is to "weave" an adjacent green branch into place, and hope that it fills out enough to hide the damage.

Your photos indicate that you have already sheared the hedge. The first photo shows that you have cut slightly deeper than desirable in the center of the photo, but there may be enough green left to recover. Time will tell.
The second photo shows two adjacent plants. The plants are well on their way to filling in the gap between them. Th right-hand plant has been overpruned, as noted above.

Shortening this conifer hedge will not cause it to fill in faster, or more densely, below.