when and how often should I prune and trim a cedar hedge .
Thank you for your question for Toronto Master Gardeners.
As you are aware, there are ideal times and methods for pruning all types of trees. Now is a good time to give the hedge a shearing, and not just the outside, but between the shrubs too. Use a clean, sharp hedge shear and remove up to a third of the needles. Do not cut back to bare branches, as the lateral growth that may be stimulated will not occur at that point.
For more information on cedars and pruning read: http://mark-cullen.blogspot.ca/2010/09/cedar-hedges-investment-that-grows.html
- Pruning Made Easy: A gardener’s visual guide to when and how to prune everything, from flowers to trees by Lewis Hill
- The Pruner’s Bible: A Step-by-Step Guide to Pruning Every Plant in Your Garden by Steve Bradley
Cedars naturally grow in wet ground so regular watering is a must, especially in drought conditions. Watering must be deep so a light sprinkling on the top of the soil is of no use. Mulching is important to hold that water in the root zone, deter weeds and shade the roots.
Feeding regularly is important as well. A fertilizer that can be dissolved in water and applied directly to the root area will allow more of the nutrients to reach them. Topdressing with sheep manure compost or regular compost will not only feed the hedge but will also improve soil structure and encourage beneficial macro & micro organisms.