indoor cat digging in plants?

My eight month old cat has began digging in my plants. She is an indoor cat because I live in a house very close to a busy street and our neighbors have had cats hit before. I can tell she wants to go outside because she tries to run out when I open the door but it's just not safe. When I move, which will be when I get out of college in a couple years, it will be to a safer neighbor hood where she can play outside all she wants. But until then is there something I can do to help her plant digging? I'm guessing it's because she wants to go outside but I"m not sure so any advice as to why she is would be great too. She's already spayed if that makes a difference.
Julianne

p.s. I also just got another cat that she is having problems adjusting to, could that be a reason why?

Hi!

Many cats like digging, I'm not convinced it has anything to do with wanting to go out. I've prevented excavations in my flower pots by covering the dirt with differend sized rocks. It looks cool too!

BTW, have you considered taking her out on a leash?

That is the perfect age to stop this behavior. Untill you can get rocks for the surface of your house plants, move them out of reach and make a point of this is not good.................It works! You just have to condition them the same as claw sharpening, its ok in designated areas. Really has nothing to do with indoor only, just natural to dig for them.

If cats see earth they will dig - it is as simple as that. For them, that is what earth is for. You have to cover it. Rocks are great or make circles of cardboard to fit the pots and make a cut to slide it around the plants. I also taped a plastic bag over the earth once, leaving a hole to water through.