I was watching "My Cat from Hell" on the animal planet. and Jackson Galaxy, a cat behaviorist, suggested to a family that making a "cat garden" containing things such as parsley, and sage to help with digestion, hairballs, and as a treat. Those are a few alternatives to the rye, barley, and wheat grass, and can be easily found in your supermarkets planted and ready for your cats enjoyment. Just be sure to plant them in a sturdy planter. Cats do not have teeth for eating plants so they have to sometimes tug to get bits of the plants. So be sure to make the planter solid enough just in case.