A few years ago a pregnant female was dropped off here and there was a cat population explosion. I was unemployed at the time and it was difficult enough feeding all of them, let alone seeking vet treatment for all of them. The first batch of kittens wasn't so bad, but the 3 females from that litter that I was unable to find homes for all got pregnant and had litters the same week, 6 each. Suddenly there were 24 cats here! A friend of mine said she felt like she was visiting Big Edie! LOL (Gray Gardens). We finally found homes for most and a no kill shelter that accepted the rest of the kittens. It was tough, I really wanted to keep them all. They did wreak havoc on my potted plants though- potting soil was apparently a great place to poop!
Thankfully rust and mildew aren't problems I see here, and being on top of this hill the exposure and air circulation are good and keep blackspot from being much of a problem. I have a few that drop most of their leaves in mid-late summer, but they just become almost invisible and just blend in with the garden around them.