If the landlord isn't willing to do anything, then that's pretty much where it ends, unless you can have a civil conversation with your neighbor and explain the issues.

I spent quite a bit of time in Cactus country and one of the things you have to do is wear shoes. It may not seem fair that this was thrust on you, but without the landlord or the neighbor willing to make a change, it's up to you to protect yourself. Sorry.

Good Luck

The land lord won't support you, so you really only have two choices. Break the lease and move, or live with it.

I would never advocate a vandal take a shovel and remove the offending plants during the middle of the night. That would be illegal, but you can always hope someone commits Vandalism.

maybe you can talk to a lawyer about this

Your side of the car port, then that sounds like your dirt. So, if it is your dirt, ask the landlord if YOU could plant something on their side of the car port... Sounds fair to me ..... Maybe some nice rose bushes ???

I live in a duplex, & our downstairs neighbors have planted a few small cacti at the end of our side of the carport & right next to ours & their walkway to our porch steps. My mom has stepped on them with her shoes on & gotten poked through her shoe. My sister & cousin also have tripped over it & gotten poked. Well my 2 year old was playing barefoot in the backyard, swimming in her pool & being a kid & she ended up tripping over something & stepped on it. It took over 45 minutes to get all of the needles out of her foot. The landlord is defending the neighbors saying my daughter needs to be wearing shoes outside & that we all need to learn to walk around it. Is there anyone else I could take this to to get the damn things moved? They're on our side of the carport, & right beside our walkway where everyone has to walk. I feel it's unfair of them to expect me to be alert & constantly wear closed toe shoes in my own backyard.