Communal garden - council keeps destroying our plants
I live in a block of flats so our garden is shared between 4 different households. However only myself and the lady on the ground floor actually use it. I don't have many plants, only two actually. A mint plant my grandma bought from the store, was only meant to last 4 months in the kitchen but planting it outside gave it a new lease of life and it's been going strong and flowering even.
My grandma then bought a rosemary and again it wasn't faring well indoors so I put it in the ground outside, again it's started to flourish from being outdoors.
The problem is that whenever it comes to summer and the council men come to do work on the plants in the area, depending on who's on the job I can sometimes come back to find the mint completely gone. Fortunately the rosemary hasn't been affected because I was able to tell the guy this time, but I'm not always around. Another neighbour on the opposite side lost her lavender to the strimmers and the lady on the ground floor lost her shrubs to it too. We have tried putting little fences around them but they just got mangled by the council guy's lawnmower as he went right over them and the plants too.
They also use weed killer so one side of my rosemary is all yellow (the side closest to the path, you can see the strip of yellow grass). I'm reluctant to even use it any more in case there are still poisons in the plant.
I have emailed the council many times about this right back at the first incident and they always deny that it happened but that they'll give their guys a 'talk' anyway. Nothing ever changes.
Do I actually have any rights to that bit of garden downstairs? Or is it owned by the council?