Problems with a neighbor

We have a neighbor who tries to cut all the green between our houses. This green was one of the reasons why we bought the house 8 years ago. I try to find our property lines. When I have them we will have to talk to him. Ugh...
He is old, Trump voter and kind of crazy. Fears fires, compares our coastal Oregon with the region in California where the Paradise Fire took place two years ago.
We have had a particularly cold and wet, more rain than normal spring this year.
Annoying business!