Nepeta Cataria: Commonly known as Catnip
Catnip is a favorite herb of mine. I have grown it for years. It is, when left to its own devices a large and sprawling plant, which will spread quite readily if not restrained. Classified as a herbaceous perennial, it is not long-lived, but self seeds readily, so once you have it, it is not difficult to maintain in the garden. Catnip can be easily propagated by seed, stem cuttings, or root-ball division. When plants are five inches or so tall, thin them to stand 12 to 18 inches apart. Reputedly, it produces a better crop when started in Autumn, and I did quite successfully start my current plants late last summer. It is drought tolerant and deer resistant. Being in the same plant family—Lamiaceae— it has the square stem and toothed leaves reminiscent of the mints.
In the garden, Nepeta (catnip) deters flea beetles, aphids, Japanese beetles, squash bugs, ants and weevils. Use it as a companion plant or steep fresh catnip in water and spray on plants to aid in keeping insects away. The oil of this plant is also an effective mosquito and fly repellent, though it has not been successfully used on human skin.
Though Catnip causes many cats to act quite foolish, it has traditionally been used by humans as a relaxant and digestive aid. The dried leaves, or whole flowering tops and leaf, may be used as tea, sachet, or tincture. The tea is considered by herbalists mild enough for children, and useful as a remedy in cases of stomach distress, headache and sleeplessness. For more information, or to obtain the dried herb, check out Mountain Rose Herbs.