Maintaining globe cedars

(Question)

I have two globe cedars on the north side of my house. They have grown quite large – higher than my eavestroughs and from the outside they look very full, but they are hollow inside. I would like to prune them back as they are starting to block a couple of windows but I am concerned that there will be no foliage left if I do that. As I mentioned, they are on the north side of the house and the soil is usually quite moist. We are located in Gimli, Manitoba – Zone 3.

(Answer)

We have responded to several questions about pruning cedars, and I suggest that you take a look at these. I’ve listed the most relevant ones below, but you could also search on our website, for example using the search terms “pruning cedar” or “globe cedar”:

  • Pruning globe cedars was posted in August 2012. The University of Saskatchewan  advises that the best time to prune your cedars is in the spring, before they start to grow. Importantly, pruning after mid-July (it is now mid-August) should be avoided, as this could weaken the plants.  Another response with the same title, (we’ll call it Pruning globe cedars (2),  posted in December 2014.
  • How to/can I trim a damaged globe cedar?  (posted in early August 2012) provides information about how to prune the cedars.
  • Pruning/trimming globe cedars, which was posted earlier this month, gives some helpful advice on shaping the cedars, when you do prune them. This article also refers to the Prune your cedars cautiously article mentioned above.
  • Globe cedar pruning was posted in April 2014, and shows a sad photo of globe cedars that have suffered dieback. We note that after pruning, the cedars will not look good, but that it is important to remove all dead wood, then wait to see how well they rejuvenate. It may take some years for them to recover, but this posting highlights the need for patience.

So, as set out above, amend the soil now (if needed) and make sure the cedars are getting enough water.  Then relax and prune them next spring before they start to grow, and start fertilizing in late spring.  Done properly, pruning should not only improve the health of the cedars, it should encourage a more bushy growth (and get rid of those hollows!), as well as help maintain size and shape.

Finally, please note that we generally provide information that is relevant to gardeners in Ontario.  For further information (e.g., for best times to prune and fertilize in your weather zone), you may want to contact your Manitoba Master Gardener Association, which has a terrific website, including “Ask a Master Gardener”, which provides an email address where you can forward questions.