Watching an old sycamore taught me something about root pruning

There's this giant sycamore down on Elm Street in my town, been there probably 80 years. Last week I noticed the sidewalk was buckling bad from the roots, maybe 4 inches of lift... I spent 3 hours digging around the roots to figure out where to cut, and halfway through I realized I was just guessing. Has anyone here had luck with a specific technique for root pruning near pavement without stressing the whole tree?

2 comments

2 Comments

elliot_miller2220d ago

I did this exact thing with a 60 year old maple in my front yard. The key is to make clean cuts at least 18 inches from the trunk and never remove more than 25% of the root mass in one season. I used a sharp pruning saw and cut flush with the sidewalk edge, then painted the wounds with pruning seal. The tree showed stress for about two weeks with some leaf droop, but it bounced back fine by the next month. If you're just guessing at where to cut, step back and look for the thicker structural roots first.

jackson.jenny20d agoMost Upvoted

That 25% rule is exactly what I needed to hear because I basically went at my roots like a hungry beaver with no plan. I dug down maybe 2 feet near a big structural root and realized I was basically just hacking at it blind, like trying to give a haircut to someone wearing a bag over their head. I pulled out the tape measure and found a root about 3 inches thick that was less than 8 inches from the trunk, so I backed way off and started measuring from the proper distance instead. Now I'm sitting here with a half-finished hole and a pruning saw, wondering if I should just pour myself a drink and call it a day.