I have a globe cedar in my front yard. It was planted six years ago. At that time I was told that I was already 5 year old by the land scraper. Over the years my husband trimmed it a bit but it is so big now it’s blocking everything behind it. It is about 4 ft tall and 5 ft wide. Can we trim it back 12 inches all around to the desired size. When should we do the trimming.
Thank you for writing, and for including your photo: this always helps us, and our fellow gardeners, with better understanding the issue at hand — in this case it appears that your cedar is indeed fairly healthy, with evidence of lighter, dense, new growth. First, I would commend that your husband “over the years (he) trimmed it a bit”, because that is exactly what globe cedars need. Regular, but modest pruning. Now, doing the math, that cedar is eleven years old, mature, but old aged! And it’s shape lives nicely up to its name. But you are unhappy with the size— yet, it does appear to be providing a nice ‘buffer’ from the street beyond.
If you really prefer to prune a bit more than usual, and mid-to-late spring is a good time to prune, here’s a sampling of some of our replies to like-minded gardeners, reminding you, above all, that new growth will not rejuvenate on bare cedar branches. So, to answer your question, 12 inches in on your plant may take you to bare wood. Prune frugally.