We have two cats (both female, 6 & 4 yrs old). The older one is becoming less mobile (can't get over the fence), and has started taking to digging up the lawn to do her business. Whenever I see her do it I run and shoo her away, which seems to work for a day or two, but then she starts again. There is a border along the edge which we don't particularly care about, and I've seen her use that before.
I saw a related question for dogs: Is there anything I can put on my lawn to prevent my dog from digging? but I don't think that answer would work for our cat.
We could go back to using a litter tray but that seems an awful pain. Does anyone have any ideas on ways to encourage her to go elsewhere? I saw this article Natural Cat Repellents which suggests growing catnip plants and/or a sandbox. But how healthy would a catnip solution be in the long term for the cat? And I'm not sure about a sandbox, since we have a young child (and another on the way!) who would probably make a beeline for that as soon as our backs are turned!!
Any help appreciated.