Hello
I have a question about shallow digging near a large cedar hedge and damage to the roots and cedar itself. How far from the hedge does the lateral root network go, and can a cedar sustain some lateral root damage from this shallow digging?
I live in Toronto and have a nice large established cedar hedge (25 year old emerald I believe). The hedge is healthy. I want to put a shed base near the hedge and I need to dig about 6 to 8 inches. I attached a picture to show the dig site and it’s position to the hedge. The dig line is 8ft from the hedge trunk line and 4 ft from the dripline.
I would appreciate your expert opinion.
Thank-you for contacting Toronto Master Gardeners with your question.
Emerald cedar (Thuja occidentalis ‘Smaragd’) is a popular hedging choice but these shrubs can be problematic if they do not receive enough sunlight or if they are grown in wet soil conditions. Having said that, your shrubs look healthy and beautiful! Emerald cedars have shallow, fibrous root systems. Normally, the roots do not spread much beyond the dripline. Your excavation, 4 feet from the dripline, should not cause significant root damage. Your shed structure may, however, reduce the amount of sunlight the lower part of the plants receive (directly across from the shed). This may lead to a diminution in foliage density and some dying out over time. It will really depend on how much of the sunlight is blocked, and for how long each day.
You can find more information about these cedars and their requirements on our website. Just type ‘emerald cedar’ into the search box under ‘Find it Here’ on our home page.
The following link is to an interesting piece with detailed specifications on Emerald cedar:
https://studiousguy.com/arborvitae-root-system/
Good luck with your shed construction!