My 12 ft high Eastern cedar hedge has seeds growing on it . If I trim the hedge, I’ll cut off the seeds. Is that OK? I want to restrict lateral growth as much as possible. Ottawa Ontario…
U-shaped hedge facing South, West, and North.
picture facing South and North.
Thank you for contacting the Toronto Master Gardeners with your inquiry.
From your photo it is obvious you have a well tended and mature Eastern White Cedar (Thuja occidentalis) that may need a bit of pruning. You will not damage the hedge by removing the seeds in the process. The seeds are a good food source for a number of birds. Perhaps you could collect some seed clusters after pruning and leave them for the birds. Your dense hedge also provides excellent shelter for birds and other animals from weather and predators.
Usually a cedar hedge is pruned in June, however Mark Cullen’s advice is that you can prune until September as long as the temperature is not too high.
https://mark-cullen.blogspot.ca/2010/09/cedar-hedges-investment-that-grows.html
You may find this previous Master Gardener post on pruning Eastern White cedars of interest before you start your task: https://www.torontomastergardeners.ca/askagardener/pruning-mature-white-cedar-trees/
The Ontario Government has an interesting document on Eastern White cedars. https://www.lrconline.com/Extension_Notes_English/pdf/cdr.pdf
I am sure you will enjoy your beautiful white cedar hedge for many years to come.