Cutting Surface Roots?

[UpNorthAdam]

Hi all,

New to the forum. I am in Manitoba Canada and know very little about trees (I build airplanes

I am planning on installing some edging pavers around some trees, and fill in the areas with river stone or mulch. These edging stones require me to dig a 4" wide by 4" deep trench (using a gas trencher). I have marked (in green paint) where I want to cut but am hesitant to cut through any roots.

See pics. Is there a radius away from the trees that I can safely cut?

Thanks,

 

[Jed1124]

In your specs you are indicating inches, is that correct?

 

[Jed1124]

4” wide by 4” deep?

 

[ATH]

I'd rather not have it trenched at all, but if you are set on it, go with the wider dashed line.

Why do you need to go 4" deep? Shallow would be better

Don't add more than 3" of mulch of the root system and don't pile it against the trunk.

Finally: no landscape fabric or plastic under the rocks or mulch. That stuff is not good for the roots as any of it restricts air and water movement. It also keeps the decomposing mulch away from the roots...the tree would love to have some of that. (That, and doesn't work very well for long-term weed control...they just grow in composted material on top of it in a few years).

 

[UpNorthAdam]

Wow, quick responses.

Yes, the edging stones are 4" x 4" x 12" long and interlock at the ends to make a border. Maybe I'll go down 2", which will create more of a barrier to hold in the mulch as the edger will stick up above ground by 2".

What are the general thoughts on river rock around trees?

 

[Raintree]

Spruce is the number one residential tree species I see for blow down calls. Shallow rooted with a big sail profile. I would not recommend cutting any roots. Lay your edging on the surface and mulch not stone.

 

[ATH]

Stone looks nice, but serves no real benefit beyond that. Mulch is wonderful for tree health (unless it is too deep or piled against trunk, at which point it becomes a detriment).

Maybe just cut the sod out and set the pavers in that gap. They will settle in over time without the need to cut any tree roots. 2" is certainly better than 4"...and like you said that would hold the mulch in.

 

[under_the_hill]

What are the general thoughts on river rock around trees?

River rock as a mulch can end up bring a lot of heat to tree roots if sunlight is directly reaching the rock, especially darker colors. The rock heats up similar to pavement vs wood mulch which is an insulator even when dry and is more likely to have some moisture about it than rock. I'd like to take some actual temperature measurements to be sure, but I don't like to see rock as a mulch where I am.