How to stop cats from coming into the garden?

[Alice-Bee]

Sister swears putting human hair in the garden (lawn) will deter cats.

Gag. I hate loose hair, when I have to pull it off my brush it freaks me out...and drain hair...

 

[kazyeeqen]

Sister swears putting human hair in the garden (lawn) will deter cats.

Or we could pee along the perimeter of the yard. Just marking our territory...

I guess that's how you communicate with cats, but I'd rather be able to just say, "Hey, not a bathroom, dude, go somewhere else."