https://en.wikipedia.org/wiki/Imprelis

https://en.wikipedia.org/wiki/Aminocyclopyrachlor

http://msue.anr.msu.edu/news/imprelis_update_for_spring_2013

The half life of the stuff is a rather high 100 days. Since the stuff was pulled in July 2011, it was essentially gone from the soil in 2013. The impact on grass was always minimal to none, so that's not a concern.

Unless somebody is dense enough to still be using the stuff, it's not a concern for new trees.

I was raised to get permission to access others property. I had a neighbor who allowed me to use his sidewalk mid block as a shortcut to go to school. if we cut across a farmer's field ( with permission ) we walked between the rows of crops & made sure all gates were closed behind us. 5 years ago I came home to find a 2 ton truck in MY yard so a roofer could throw the shingles off of my neighbors roof into the truck. then the guy had the b**ls to lie & say he thought he was on the neighbors property. he was on my side of my fence. last year I happened to be in my yard & found tree trimmer looking at a neighbors tree. when I approached him he announced that he'd be in my yard while removing the tree. so- i asked him if he was asking if he was asking for permission to come on my side & he gave me a puzzled look. asking permission never occurred to him. THEN he asked me who the f**k I thought I was? so I told him I'm the man who owns this land & that he could get the f**k off of it. if he had asked I'd have said yes. I explained what happened to the neighbor when he asked why I refused permission & he hired someone else.

+1. Contractors for other people may not enter your property without permission. Good ones won't ever ask because they'll never set foot off the property that's being worked on.

Maintenance easements can be entered by city (township, whatever you have where you live) personnel, of course. But those easements don't apply to anybody else.