Should I cut this root in the path of french drain?

April 15, 2017 6:16 AM

Hit a snag when digging my french drain trench-- pair of roots 31 inches from a trunk 23 inches in diameter. Should I or cut them?

I am installing an EZ-drain french drain behind a rock wall that I am building, and I encountered a pair of roots in my path that is about 31 inches from the trunk (trunk is 23 inches in diameter). They are about thumb size thickness.
The quickest easiest fix would be cutting the root, but I fear harming the tree. I can't really build up the slope next to it because I need the depth. I can leave the pipe sit over the root, but it may leave some water sitting there. Would it be smarter to cut the root or leave a hump in my drain? Many thanks!

Trench photo
Trench photo 2
Root

posted by Mikey51 to Home & Garden (9 answers total)

I'd cut it, knowing I'll probably have to replace the French drain in 5 or 10 years because of the presence of roots. There are root kill products you could use to try to protect from root occlusion, but I have no ide whether they work or if they'll give you cancer.
posted by Geckwoistmeinauto at 7:33 AM on April 15, 2017 [1 favorite]

If cutting a branch off the tree that size won't kill it I would feel fine about cutting off a couple of roots. I am not an aborist, but trees are pretty resilient once they have been established.
posted by saucysault at 7:35 AM on April 15, 2017

Cut the root AND prune a few branches up top. Balance the decreased water supply with decreased demand. We can't see the top of the tree and you don't tell us what kind it is but as a guess I'd probably take a handful of thumb-diameter branches off as a rough minimum.
posted by SaltySalticid at 7:58 AM on April 15, 2017 [3 favorites]

Response by poster: Thanks for the info thus far. I don't know anything about trees but here is a picture of the buds. I just moved here.

Full tree
Buds
posted by Mikey51 at 8:25 AM on April 15, 2017

I'd cut that without hesitation.
posted by humboldt32 at 9:23 AM on April 15, 2017

With additional pics yeah you're fine to cut. Probably don't strictly have to prune at top but I would if I liked the tree. Removing one wrist-sized branch may be a better/easier option than more smaller branches.
posted by SaltySalticid at 12:27 PM on April 15, 2017

Your tree is a dogwood.
I think you're okay to cut roots but do try to avoid doing so in the future. Ditto on avoiding compacting the soil around it.
posted by sciencegeek at 2:03 PM on April 15, 2017 [1 favorite]

I wouldn't cut those roots.

Roots are like tensioning cables, especially in a wind, and while it doesn't look like that house in the background would be damaged if your tree blew down, that ornamental fence and the power lines would be.
posted by jamjam at 4:22 PM on April 15, 2017 [1 favorite]

I can't tell what kind of tree that is - if it has shallow roots, don't cut those roots as they are holding the tree in place. If it has deep roots, then cutting the more shallow of (many) roots shouldn't matter. Find out the tree type and google their root structure to see.
posted by Toddles at 10:12 PM on April 15, 2017