Plant catnip in a place where your cats can rub and roll in it without hurting adjacent plants. Some cats like catnip so much that they lie on it, roll on it, and chew it to the point of destruction. If you find that to be the case, place some 1-2' long bamboo sticks or thin dowels every 2-3" wherever you’re growing catnip to make it impossible for a cat to lie on top of the plant. Try planting Catnip in front of purple echinacea (or coneflower), which blooms about the same time. The plant bears tiny, white blooms that are not very showy. You can also grow it in containers. Also consider growing catnip near the vegetable garden as a way to attract your cat and thereby keep down the rodent population. Keep plants full by pinching the growing stems and flower buds when they appear.