Cat Repellent

To keep cats out of your yard, you can use Citronella, the same thing you use to repel mosquitoes.  You buy it in a concentrated form, an essential oil, and mix a few drops with water in a spray bottle.  You then spray it around your yard and in your plant boxes ^{(Not directly on the plants)} and it is supposed to drive cats nuts and keep them away.  You can find it at your local GNC, General Nutrition Center.