Catnip and Catmint Are Often Confused but They Are Different Plants
Catnip is Nepeta cataria, the famous plant that intoxicates cats. Catmint refers to any of several plant species also in the genus Nepeta, especially Nepeta faassenii, N. racemose (formerly N. mussinii), N. subsessilis, and a number of hybrids.
Catnip is the most famous species of Nepeta and is generally not called catmint, although not everyone makes that distinction. The problem is that Nepeta is a genus in the mint family, Lamiaceae, and people commonly use the name of the family for plants included in it, so catnip and catmint can both be called mints, and calling all Nepeta species catmints is reasonable, but in this case, not helpful.
Catnip has a long history as a minor medicinal plant in Europe, usually used as a strengthening tea. It is one of only a few plants that cats react to by acting euphoric, which has promoted growing it. It was brought from Europe early during settlement and by 1670 had escaped from New England’s boundaries. Today, it is found in every state in the continental United States and most of Canada. It is mildly invasive.
Catmints were brought to North America from Eurasia more recently as garden flowers. They may contain the cat-attracting molecules of catnip, nepetalactone, but in much lesser amounts. A couple species have escaped as weeds in some parts of North America, but most are found only in the gardens where they were planted.
As you would expect from plants so closely related, both catnip and catmints share many characteristics. All are upright perennial herbs with square stems and opposite aromatic leaves. The flowers grow from a flower stalk that extends above the plant. The flowers are very attractive to bees and butterflies.
They are easy to distinguish, however. Catnip grows about three feet tall. The pale to medium green leaves can be 2.5 inches long. They smell faintly minty (or, like catnip, if that’s a smell you know). The flowers are white. It flowers in midsummer.
Catmints are mostly shorter, growing to about two feet tall. The flowers are typically intensely purple or lilac-blue. They start to flower in the spring and will continue all summer. The leaves are dark green, relatively small. Some smell minty, others have a smell that reminds me of turpentine.
For cats, grow catnip. As beautiful garden flowers, grow catmint.