With the Crazy Cat Plant, catnip is very easy to grow! Once they have grown a little, harvest some foliage, crush it up, put in the included linen bag, and watch your cats roll over, purr, and leap with excitement! The secret is that when you crush the foliage of this herb, it releases an oil that attracts cats. In fact, cats will rub up against the foliage themselves to bruise it and release the scent. You can do this with fresh or dried catnip leaves.