You know, I have been staring at those two pictures for the last hour. After I read the comments, I just stared, while uttering the mantra, "the problem is the solution" over and over in my head.
Wow, a picture
is worth 1,000 words.
But first, a comment on how to prepare.... Read all
city, county and state ordinances regarding the property and any HOA kinda things. Understand what they truly mean. For example, I had a neighbor tell me I had to "spray with death spray" my fruit trees. I looked at the ordinance it states, "you must manage the pests" that can come to the tree. I thought, OK, I will plant garlic, create habitat for
bats and dragonflies, make sure the soil is healthier, sticky traps. If anyone asks me,
I am "managing the pests". If the officer is unfamiliar with this form of pest management, I would invite them to find the pests and view the research I found.
Recognize their beauty and resources ... No one likes to talk about them-self more than your (figurative) neigbor. You may consider complimenting them on how green their lawn is (OK, maybe not). However, I love those trees. Maybe you do too? Maybe it would soften their heart to talk about them. Be jealous in front of them for the tremendous resources they have every fall. If they are "smart" enough to chem their yard, they should be "smart" enough to throw that resource away. You could encourage them to create some kind of life on their side of the fence (all along the fence) that utilizes the resource they would normally throw away. Or you could say something like, "with your permission, I could use this resource on my side (along the fence) to benefit us both." You can do a similar thing with their tree branches of both their coniferous and deciduous trees. This way the neigbor can benefit from the resource that they provided. That will give them "skin in the game". Make the benefit wide so that the spill of the "chem" onto your yard does not kill all of the benefit. Try to have your neighbors realize that part of the benefit was killed by their own application of chem.. Constructing the solution this way, they will keep tabs on that "benefit you planted". In other words, make them part of the solution.
What they hate... I am going to guess, that besides the music and dog issues, the neighbors do not like the
dandelions growing in your yard. They probably think that is why they have dandelions growing in there yard (need to chem it). They may be holding it against you but not telling you. If they are cheming the yard chances are good they feel this way. Recently, I had a neigbor come onto my property applying chemical stuff to my dandelions. WTF? Not quite sure how to deal with the "spread of weeds" perception, but maybe you could let them know how you are "managing" them.
Bamboo is a
root propagator and some use the word "invasive". It seems to me, if bamboo is used, the neigbor will eventually perceive that you are "invading" their space (I know, they are invading yours with the chem). Bamboo could be a mutual decision between you and your neigbor. This may give you the barrier you seek, but will not necessarily improve relations.
So what do you most want to do? That is the $64,000 question.
edit: I would use the left over manure from your
chicken house (you know the ones the neighbors had you remove), to apply to the "benefit along the fence" and make sure the neighbors know you did that (eventually).