A city inspector called my root collar excavation 'shallow' on a job in Tacoma.

He pointed at a maple I'd just finished and said, 'You're only going six inches down, that flare is buried deeper than that.' I went back with a hand trowel and found the true root flare another four inches under soil and mulch. How deep do you all typically go when you're exposing the root collar on mature trees?

3 comments

3 Comments

miles94827d ago

Man, I gotta disagree with that inspector's take. Going super deep every single time can do more harm than good, especially on an older tree. You can cut way too many roots and mess with its stability. I usually just go until I see the first main lateral roots flaring out, even if it's only a few inches down. Sometimes that flare really is just buried shallow.

coleman.taylor26d agoMost Upvoted

Wait, you only go down a few inches? What happens when you hit a giant root right under the surface? I've seen trees where the flare is buried a foot down under old fill dirt. If you stop at the first root you see, you might leave the whole trunk base still covered. That's asking for girdling roots and rot later on. You gotta at least clear enough to see the actual trunk shape start, even if it takes some careful digging.

emeryfox23d ago

Yeah, I used to stop at the first lateral too. Seeing a trunk flare buried a foot down changed my whole approach.