   Catnip - September 17, 2003 Jeff Schalau, County Director, Agent, Agriculture & Natural Resources Arizona Cooperative Extension, Yavapai County Catnip (Nepeta cataria) is native to Europe and a close relative of the mints (spearmint, peppermint, pennyroyal, etc). Many cats are attracted to the plant or dried herb and the smell can trigger strange behavior patterns. Some of these behaviors include licking, chewing, head shaking, chin and cheek rubbing, rolling, and salivation. Only about two-thirds of domestic cats respond to the herb. Lions, leopards, jaguars, and other cat species are also affected. Catnip is also used as a folk remedy for fevers, colds, cramps, and migraines. Aside from pleasing cats and healing humans, catnip also has insecticidal properties. The active chemical in catnip is nepatalactone (a component of essential oil extracted from catnip). Researchers at Iowa State University have recently patented nepatalactone as a repellent for cockroaches, mosquitoes, mites, ticks, spiders, termites, and other insects. Currently, the active ingredient DEET (N,N-diethyl-m-toluamide ) is one of the most effective mosquito repellents. However, many people are not comfortable using DEET because it has been implicated with seizures in some children. The use of nepatalactone containing catnip oil as effective alternative to DEET seems encouraging. However, catnip oil has not undergone thorough toxicological testing for use as a topical insecticide and there might be some unforeseen problems. A pesticide is a pesticide: just because it comes from a plant does not make it safer to use. Catnip oil also shows promise for use in crop protection. In a study, catnip intercropped with collard greens (planted in alternating rows) reduced the number of flea beetles: an insect very damaging to collards. Extracts of catnip have also been shown to eggplant from adult and larval stages of Colorado potato beetle and attract beneficial insects. Catnip extracts are not effective against caterpillars or moths and butterflies, but have been used as an antifeedant for deer, rabbits, and squirrels. Overall, catnip has great potential as a pest control agent. Catnip is relatively easy to grow, tolerates a wide variety of soils, and probably has potential to invade your garden and beyond if not kept in check. Seed is available from many seed companies. The seed is very small and can be directly sown on well prepared garden soil and covered with 1/8" of soil. Alternatively, it can be sown in a flat and transplanted after it gets 5 sets of leaves. If you have cats, you may need to protect it from them until it becomes mature and established. Once established, each individual plant should survive for several years. Established plants can also be divided by cutting the root mass in half and replanting. The plants can get fairly large (3 feet tall), so grow them where they have adequate space. To harvest catnip for tea and for cat fun, cut stems prior to flowering (early to mid summer). Remove leaves from the stems. Place the leaves on a screen or tray in a well-ventilated area out of direct sunlight. Turn the leaves once a day to provide aeration. After two or three weeks, it should be dry enough to crumble into flakes. Put dried flakes into a sealed jar or ziplock bag for storage. If you are a cat lover, a few catnip plants will provide a year round supply. Catnip is a versatile herb that also has great potential for use as an insecticide and integrated pest management tool. As traditional pesticides are scrutinized, new and potentially safer alternatives will become increasingly popular. Catnip will surely be included among those being considered. The University of Arizona Cooperative Extension has publications and information on gardening and pest control. If you have other gardening questions, call the Master Gardener line in the Cottonwood office at 646-9113 ext. 14 or E-mail us at mgardener@verdeonline.com and be sure to include your address and phone number. Find past Backyard Gardener columns or submit column ideas at the Backyard Gardener web site: http://ag.arizona.edu/yavapai/anr/hort/byg/. |