Plants and trees have been a pain with Pets also - especially horses and palm trees set together to form a V at the base - well the horses somehow seem to get stuck between them - so I had to go around to all my beach lots in ever hood I have and make sure there was enough space between the trees - which needs at least 2 full spaces not to get that problem.
Also look out for fences less than two spaces from buildings or if you block off a flower garden on a community lots, tourist and horses like to spawn in them for some weird reason and will bring your game to a stand still kind of freeze.
It is a real pain. The sims team need to add a line in their programming that nothing spawn in an area that is closed off - or something.
But with driveways and houses and drive ways and plants - they have been weird like that since Ambitions came out.
