As a treat for my cats, about seven years ago I started growing catnip (Nepeta cataria, Lamiaceae) in my garden. At the time I didn’t know this mint is an introduced species that became widespread across North America (Brandenburg 2008). Some people consider it invasive, but it doesn’t seem particularly aggressive. Since becoming acquainted with it, I sometimes notice it growing in different places. Last week I came across this large group of robust plants on a forest/field margin here in southeast Michigan.
Catnip is, of course, famous for its effect on many cats. It produces an organic compound called nepetalactone that creates a sort of euphoric high when sensitive cats sniff it. At least fifty percent of cats react to it, and sensitivity has a genetic basis (Barry 2005). Although all five of my cats are interested in it, only three are susceptible to the intoxicating effect. Two of the strongly sensitive cats are brothers, and one that isn’t sensitive has a sister who isn’t either. Those that react strongly chew the catnip, roll in it, and are generally mellow and entranced by it. The two that aren’t sensitive sniff it and taste it, but seem relatively indifferent.
Catnip also has numerous applications related to entomology. Nepetalactone, the same compound that makes cats giddy, can also repel mosquitoes more effectively than DEET. Another compound in catnip called iridodial has been found to attract beneficial lacewings that eat pest insects. Catnip oil has also been shown to keep stable flies away from cattle. In addition to the entertainment value this plant has for cats, it could prove to have great economic importance in controlling insect pests.
Barry, D. 2005. Catnip. Chemical and Engineering News 83(31):39.
Brandenburg, D.M. 2010. National Wildlife Federation Field Guide to Wildflowers of North America. Andrew Stewart Publishing, Inc., New York, NY.