Trespassing Neighbor Mowed My Native Meadow. Looking For Any Extra Advise!

I bought a 1/3 acre lot from my township just over four years ago. It connects to a sliver of my house’s lot in the northwest corner and it made sense to buy it. It’s zoned for conservation so it’s easy on the taxes but it severely limits building, which is fine with me. As soon as I closed I immediately set to seeding it with over 150 native wildflowers. I’ve also planted two oak trees, and a poplar and a myriad of native shrubs. I also installed three signs on freestanding posts marking it as a meadow restoration (please don’t mow/spray kinda thing, bought them from Prairie Moon). Trying to keep it open, I mow once a year in mid-March and monthly in the growing seasons along a meandering path. It’s sort of my own personal park. Today I went up to inspect it and the neighbor who lives adjacent to the northwest corner of this property had mowed a square of it, approximately 30’ x 30’, right down to an inch or so.

The only interaction I’ve had with this guy was when I first bought it and was planting some bareroot natives around the west border that abuts a thicket along a bank that drops to a railroad track. He came out to tell me one of the trees on the edge of the property had damaged his garage’s foundation with its roots. It is a silver maple, and it is 30’ from the property line. I told him then that I wasn’t aware you could build a structure within 20 feet of a property boundary without a variance from zoning. He said he built it on an old foundation and it was grandfathered in. I just said, “well, old foundations I guess. I just bought the property and I can see about maybe running a trench along the property line to cut off any roots coming your way, but I’m not interested in taking the tree down.” The conversation ended right around there from what I recollect. This was four years and four months ago.

So today I’m left with a barren patch of 1000 sq feet or so of what should be it’s first great year of flowering. I’m not sure how to proceed. I’m not trying to burn bridges since I like my neighbors that actually live next to my house and it’s lot, and a conflict would obviously make something awkward eventually. I’ve got signs and he still had to mow into my property for some reason. I’m pretty pissed because I had noticed a good bunch of flowers progressing in that area, they’d be flowering in another month.

What would you actually do?