My cat Gigi in the catmint
Catmint
The pet in the middle of the genus Nepeta gives you a hint to its usage as a plant. In this case pet stands for cat as in mint for cats. Catnip or Nepeta cataria contains neptalactone, a substance that drives many cats ecstatic. They rub themselves on the stems, roll in the middle of the plant, chew its leaves, often devour small new plants, and even rip up even the roots to satisfy their catmint lust. The act drunk, and like all drunks, some are lovey, some are mean. Mine often hiss when I try to deprive them of their drug of choice. Nepeta cataria is not a particularly pretty garden plant. Most gardens grow the purple-flowered Nepeta missinii, which is supposed to be a little less attractive to cats. Don't count on it.
After my first two failures growing catnip (cats dug up the plants and devoured them), I had to enclose my new catmint plants in cages to prevent my cats from killing them. These were the more decorative Nepeta mussinii a species from the Caucasus. Two years later the plants are large enough to survive the cat's attention, but I still have dull-ended punji sticks errupting from my plants' perimeters. This keeps them from being eaten to the ground or dug up. Many gardeners hate cats, but mine keep mice, moles and ground squirrels out of my gardens. They do a fair job on grasshoppers, too, so I like to keep my pets happy.
If you feel the stems you will notice the four ridges that make the stem feel square. This trait and strong scent of Nepeta mark it as part of the mint family. It works well in herb gardens, dry gardens, rock gardens and borders. While catmint is not a show-stopping plant, its blue-flowers last through much of the summer and the soft green-gray leaves add soft contrast among brighter green foliage. It provides a pleasant background for more vibrant flowers and helps blend plants into a harmonious garden scene Catmint has other attributes. The leaves and blossoms have an unusual fragrance and make a pleasant sedative tea. Deer aren't interested in eating it. Catmint thrives in dry, sunny locations where many plants fail. Lastly, catmint produces the substance neptalactone, which many organic product companies claim repels mosquitoes and black flies better than deet.
Hardy in this area, most garden books recommend catmint grown in moist, well-drained soil. I'm not sure how you keep well-drained soil moist, but I've found catmint like a dry garden bed better than a wet one.
Many gardeners use Nepeta as an edging plant or as a ground cover in barren areas. When locating catmint in your garden, take into account its sprawling and floppy habit. I find catmint attractive draping over a low wall, but probably would not use them where they might spread out in an untidy manner on a walkway. Some of the species seed freely, which a gardener might want to avoid.
If you are looking for a good Nepta for your garden, try the hybrid Nepeta x faassenii or Faassen's nepeta. Stronger upright stems make it seem taller than most species and give it a tidier appearance. It is sterile, producing no seeds to become later weed problems. Because it doesn't produce seed, you can't grow it from seed, but you can divide Faassen's nepeta in the spring. Cats like it as much as they do catnip, so protect young plants.
Does well in zones 3 – 8 in full sun or part shade, and is drought tolerant.