There are several constants I see after twenty- two years of growing plants professionally. One of those things is if you let grass grow up to the trunk of your tree you will ding it with a lawn mower and cause a garish wound that gets worse with time. If you do not do that you will weed whip the bark right off the base of the trunk of the tree and kill it quickly. Human nature being what it is overcomes common sense and instead of pulling that grass with your hand, cutting with lawn shears, etc you try and get as close as you can with dangerous machinery, inevitably injuring your tree.
Anyone with a brain would not do this to a dog, cat, child, their mom, so why a tree? It’s a living thing too. Often times people think a tree, bush, or perennial should be torture proof and sustain all kinds of injury and still perform perfectly. Do the Colts players pull that one off? No they do not!
That brings us to the solution to this problem- the mulch ring. The mulch ring is a ring 3-5’ across with mulch no more than 2” deep. I use pine bark mulch and generally regard most other mulch products as less than desirable. I do not use weed barrier. I place 8-10 sheets of newspaper (no glossy pages) for my weed barrier on the ground before I put my mulch down. This is a great way to keep 80% of new weeds down the first year. The bottom line is this ring creates a psychological barrier against the mower and weed whipper. You do not generally weed whip or mow mulch.
Landscapes need to be functional and be thought out to a greater degree by the masses. Too often I see people make mediocre efforts in growing things and expect incredible results. Does this work in the gym?