Nepetalactone, the essential oil secreted from the catnip plant (Nepeta cataria), is responsible for making cats behave like crazed groupies. Spikes of pale pink flowers bloom among mint-scented foliage and furry white stems. Take care when you plant this cat aphrodisiac outdoors; the local feline set will consider it an open invitation to frequent your flower bed.
Heart-shaped leaves covered with fine hair on the surface and thick, woolly hair on the reverse are the hallmark of mint-fragranced peppermint geranium (Pelargonium tomentosum). Red eyes peek out from the center of tiny white flowers that grow in modest groups among the lush, strongly scented foliage. Spreading up to 2 feet, this sprawling perennial makes a lovely addition to a container or hanging basket.
Pretty clusters of lilac or reddish purple flowers cling to the slender stalks of European pennyroyal (Mentha pulegium). The hairy, oval-shaped leaves release a heady mint fragrance when you crush them. Pennyroyal grows a foot tall, and spreads into a sweetly scented carpet.
The variegated foliage of pineapple mint (Mentha suaveolens "Variegata") exudes a fragrance that smells like pineapple. Spikes of grayish flowers appear from the mid-summer to early fall. Like the pennyroyal, pineapple mint makes an excellent ground cover that remains under a foot tall and spreads quickly.