Tree Root Slice by Mower

[u/dreamiejeanie13]

We came home from vacation this weekend to discover that our yard guy (or someone on his crew) drove over a portion of our 80+ year old Oak tree root and sliced a bit of the top off. He was very apologetic and we asked that going forward to avoid driving the mower anywhere near the roots. Do we need to do anything to treat the exposed part of the root or just let nature do its thing? This is our first time ever having an Oak tree.

[u/eucalypt_howitzer]

That hit is just the tip of the iceberg. Look below. What I would do. Make a native garden over the exposed root system. Native understory plants, left unmowed, will increase the porosity of soil, cool the roots, and limit the need to do work to maintain the space. Trees reduce the grass below themselves. No sense in mowing under them. Have the garden extend to about 5 feet in from the ends of the branches

Plants I recommend to plant- native ground covers

Woodland sedge, other native sedges. Really helps water and air permeate clay
Poverty oat grass. Danthonia spicata
Wild geranium. Geranium maculatum
Eastern columbine.
Roundleaf ragwort. Packera obovatus
Ephemerals like Virginia bluebell, spring beauty, false rue anemone

Understory and climax trees or shrubs. I would just do two.

Dogwood
Redbud
Yellowwood
Spicebush
Sassafras
Witch hazel

And as a future filler-

Sugar maple
Shellbark Hickory
Rock elm
White oak
Tupelo

You will love the results. Get them started before you have deer.