Family: Labiatae (Lamiaceae) (mint family)

Genus Notes

Nepeta has about 250 species of perennial, sometimes annual, herbaceous plants native to dry habitats in temperate Europe, Asia, northern Africa and the mountains of tropical Africa. Several species are grown as ornamentals and as ground covers.

English Names
Catnip
Also: catmint, catnep, catrup, catwort, English catnip, field balm, nep, nip
[Many of the ornamental species of Nepeta are called catmint, particularly N. ×faassenii Bergmans ex Stearn (N. racemosa Lam. × N. nepetella L., also known as N. mussinii hort.), a sterile hybrid with several cultivars.]

French Names
Family: Labiées, famille de la menthe
Népéta cataire (f)
Also: c(h)ataire (commune), herbe à chat(s), herbe au(x) chats (herbe-aux-chats), herbe-des-chats, mente à chat(s), menthe au(x) chat(s), menthe de(s) chat(s), nepeta, népéta chataire, népéte, népète c(h)ataire
[The lemon-scented variety of this species (cultivar citriodora) is sometimes called mélisse (Fournier 1947-48), although this name is best reserved for lemon balm, Melissa officinalis, discussed in this book. C(h)ataire is also used for the weed Glechoma hederacea L.]

Description, Taxonomy, and History

Nepeta cataria is an erect perennial, 0.3-1.6 m high, which produces small whitish or pinkish (occasionally blue or lilac), purple- or red-dotted flowers. The plant is strongly scented with a mintlike odor, rather like pennyroyal (discussed in this book), which many find somewhat disagreeable. Catnip is native from the eastern Mediterranean region to the western Himalayas, central Asia, southern Siberia, and China. It has been introduced in Japan, North America, South Africa, and Java. Catnip has become widely introduced in North America, and has been collected as far north as Alaska. As a weed, it is found in hedges, fencerows, roadsides, stream banks, and waste places.

Nepeta cataria var. citriodora (Becker) Balb. contains a relatively high proportion of lemon oil.

Catnip was cultivated for cats by the classical Greeks and Romans (le Strange 1977). By 1265 it was a familiar herb of kitchen gardens in England (le Strange 1977). During the early medieval period the leaves and young shoots are known to have been used as a seasoning in the kitchen. In 15th century England, catnip leaves were used for rubbing meats before cooking, and also sprinked in mixed green salads (Macleod 1968). Before modern Chinese tea became widely available, catnip tea was frequently consumed in England (Duke 1985).

Fig. 253. Catnip (Nepeta cataria), from Syme et al. (1863-1886).

Fig. 254. Catnip (Nepeta cataria), from Bulliard (1784).

Uses

The principal culinary use of catnip is as a tea, which is reputedly sedative and soporific (sleep-inducing). Fresh or dried leaves and young shoots are sometimes used for flavoring sauces, soups, and cooked foods. Dried leaves are employed in herb mixtures for soups, stews, and condiment sauces. Catnip has a strongly minty, warm, pungent, bitterish, amphoraceous taste.

The cultivar Citriodora has a mild lemon aroma that is more appealing to most people for culinary purposes than regular catnip, but less appealing to cats (Miske 1994). This lemony catnip makes a tasty tea, and the leaves can be rubbed on meat for flavoring, or candied with egg white and sugar to serve as after dinner mints (Miske 1994).

Catnip is extensively grown for extraction of its oil. Lemon oil from catnip is used in perfumes, candies, and pharmaceuticals. Nepetalactone (see Chemistry) is employed to prepare feline attractants, sometimes used on toys for cats. The oil from catnip has been used in the past as an attractant to bait wild animal traps, but has been replaced by less expensive synthetic products (Simon et al. 1984).

Catnip was once used extensively in medicine, but it is now best known for inducing a euphoric response in cats. Cats purr contentedly, tear with delight, and roll in ecstasy on the crushed leaves of catnip. Information on past medical usage and the catnip response is presented in Additional Notes.

Catnip also attracts bees, but not for the same reason that it attracts cats. It is an excellent honey plant, providing nectar for honeybees and other bees. According to Crockett and Tanner (1977), goldfinches are drawn to the dry seed heads in winter.

Recipe Sources

Catnip tea (Crowhurt 1973; Marcin 1983); Catnip tea (after Grognet 1990): Put 1 oz. (ca. 28 g) in 1 American pint (ca. 473 mL) of boiling water. Adult dose: 2-3 tablespoonfuls (30-45 mL); Child dose: 2-3 teaspoonfuls (10-15 mL). [Note: if too much tea is ingested, vomiting may occur.]; Candied catnip leaves (Gibbons 1966).

Importance

Catnip is cultivated as a medicinal plant, bee pasturage, for the essential oil, and for use as a condiment, principally in Europe, North America, India, the Soviet Union and China (Mansfeld 1986), and to a small extent in the U.S. (Ferguson et al. 1988). Less than 50 kg of catnip essential oil are produced annually in the world (Lawrence 1992).

Cultivation Notes

Soil

Dry sandy soil is recommended, but the plant also grows well (and bushier) on well-drained, moderately rich garden loam. Catnip has a pH tolerance range of 4.9-7.5 (Simon et al. 1984; De Baggio 1987).

Climate

Catnip is a hardy plant that will grow well in much of North America. Growth occurs between 4 and 21°C, optimally about 13°C. It can be cultivated in full sun but thrives in partial shade.

Propagation and Cultivation

The plant is easily propagated by seeds, which remain viable for 4 or 5 years, and may germinate erratically. They should be sown at a depth of 6 mm or less, with seedling emergence usually in 8-12 days (Wang et al. 1993). Once in place, catnip self-sows. Because catnip seeds are extremely small and seed quality is frequently low, catnip may be established by transplants rather than by direct seeding (Ferguson et al. 1988, which see for additional information on commercial cultivation). Propagation can also be by root division and stem tip or softwood cuttings. The plants need little attention, except weeding, although they themselves are weeds. Pinching the plant at the appearance of the first flower buds produces a bushy plant with superior leaf production (Crockett and Tanner 1977).

Fig. 255. Catnip (Nepeta cataria), from Johns (1853).

Catnip can be grown as a house plant. It should be provided with moist, not soggy soil, and at least 5 hours of direct sunlight daily. The plants will do best at temperatures of 12-16°C, and benefit from a commercial potting mixture supplemented with lime (Crockett and Tanner 1977). Indoor catnip tends to become straggly, and should be pruned to promote a bushy shape.

Harvest and Storage

Fresh-picked leaves can be used for teas, and for stimulating cats. Dried leaves will also serve these purposes, although not quite as effectively. The flowering head and tender herbage are cut off, dried in the shade, stripped, crumbled by hand-rubbing or screening, and stored in jars. Commercial harvesting is carried out at full bloom; when seeds begin to form, the volatile oils have decreased and the plants are past their prime (Ferguson et al. 1988). Commercial harvests of 3400 to 5600 kg/ha are normal in North Carolina (Ferguson et al. 1988). Drying needs to be carefully controlled in commercial harvests to prevent deterioration of the volatile oils, and storage should be at temperatures no higher than 40°C (Ferguson et al. 1988).

Example Cultivars

Citriodora.

Additional Notes

The response of domesticated cats to catnip has been extensively studied. Any branches of catnip that have been bruised or broken will emit the catnip chemicals. The cats sniff, then lick and chew while shaking their heads, followed by chin and cheek rubbing and a headover roll and body rubbing. They may become quite vocal. Because the reaction is similar to estrous rolling patterns, and sexual stimulation is apparent (even in neutered cats), some have interpreted catnip as an aphrodisiac. Cats take great pleasure in rolling in and eating the foliage, returning daily to repeat the experience. Catnip does not appear to harm cats.

While most domesticated and wild cats are affected by catnip, not all are "nipaholics." A dominant gene has been shown to be responsible for inheriting the response. Kittens less than 2 months old do not react or react only partially, and the full behavioral pattern may not develop until cats are 3 months old.

Fig. 256. Catnip (Nepeta cataria), from Lamarck and Poiret (1791-1823).

What benefit could catnip plants derive from stimulating cats? Apparently none. The chemicals in catnip that stimulate cats do have an adaptive function, however. They have been shown to repel many insects, and so protect the plants (Eisner 1964; Tucker and Tucker 1988). The same or similar chemicals that protect catnip are synthesized by other plants, many of which have also been shown to attract cats (see Curiosities for a list of species). Moreover, the same or similar chemicals that protect the plants mentioned above have been found in some insect species, and have been shown to protect these species by repelling other insect species. Perhaps most astonishingly, cats have been shown to be strongly attracted to some ants that possess these catnip-like chemicals (Eisner 1964; Tucker and Tucker 1988).

Chemistry

Catnip contains volatile oils, sterols, acids, and tannins. Notable constituents include nepetalactone, nepetalic acid, nepetalic anhydride, a- and ß-citral, limonene, dispentine, geraniol, citronellal, nerol, ß-caryophyllene, and valeric acid (Simon et al. 1984). Nepetalactone constitutes 70-99% of the essential oil of catnip. The main constituent attracting cats is the trans, cis-isomer of nepetalactone, which is metabolized and excreted in the urine. Nepetalic acid, a metabolic product of nepetalactone, is the most active constituent, and cats can respond to air concentrations of 1 × 10¹⁰ to 1 × 10¹¹. Waller and Johnson (1984) studied the metabolism of nepetalactone. Additional information on chemistry of catnip is in Simon et al. (1984), Duke (1985), and Duke and Ayensu (1985).

Medicine

Catnip has long been used medicinally, as a tea, juice, tincture, infusion, and poultice. The tea was used to treat cancer, insanity, nervousness, nightmare, scurvy, and tuberculosis, while a root extract served as a mild stimulant. Catnip was employed orally to treat colic, diarrhea, flatulence, hiccups, whooping cough, the common cold, measles, asthma, yellow fever, scarlet fever, smallpox, jaundice, and to induce parturition and encourage menstruation. Poultices were used for hives, sore breasts of nursing mothers, and to reduce swelling. A poultice of catnip and other herbs was employed to treat aching teeth in the Ozark Mountains (Simon et al. 1984). Catnip was sometimes smoked to relieve respiratory ailments. Despite this long list of uses, catnip is not employed in modern Western medicine, although it is still used in Chinese medicine (Duke and Ayensu 1985).

Tyler (1993) noted that no one has found evidence of harmful effects from catnip consumption, and concluded that there is no reason to avoid drinking catnip tea.

Nutrition

Catnip has good content of vitamins A and C (Gibbons 1966), but because so little is consumed no nutritional advantages have been identified.

Curiosities

• The generic name Nepeta is said to have been derived from the town Nepete in Italy where catnip was once cultivated (Bunney 1992).
• In the belief that catnip roots made even the kindest person mean, early American hangmen consumed catnip roots before executions to harden themselves for their work (Castleman 1991).
• Catnip is by no means the only plant species known to elicit the catnip response in cats (Tucker and Tucker 1988). The following have also been reported to affect cats (some notes are provided where plants may be available in North America, for those wishing to test their attractiveness to felines): Actinidia kolomikta (Rupr. & Maxim.) Maxim. (miyama-mata-tabi; occasionally cultivated in North America); A. polygama (Sieb. & Zucc.) Maxim. (silver vine, mata-tabi; occasionally cultivated in North America); Boschniakia rossica (Cham. & Schlecht.) B. Fedtsch. (a plant parasite of the roots of alders, found in northern areas); Lippia javanica (Burm. f.) Spreng.; Menyanthes trifoliata L. (buckbean, a bog plant found in North America, occasionally in bog gardens); Nemophila menziesii Hook. & Arnott (baby blue-eyes, an annual often grown in gardens); Origanum dictamnus L. (dittany of Crete, discussed in this book); Teucrium marum L. (marum, cat thyme, a Mediterranean shrub sometimes cultivated in North America); Valeriana celtica L. (a wild native of the Alps); Valeriana officinalis L. (a common valerian, garden heliotrope, cat's valerian, a garden plant that has become naturalized in Canada and the U.S.); Vaburnum opulus L. (cranberry bush, an ornamental bush with edible fruit widely grown in the Northern Hemisphere).
• Both cats and rats are fond of Valeriana officinalis (mentioned above), and it has been used as a bait for trapping wildcats and rodents (Morton 1976).
• Nepetalactone chemicals responsible for the intoxication of cats seem to be similar to the natural sedatives (valepotriates) in valerian, supporting the traditional use of catnip as a mild tranquillizer and sedative (Castleman 1991).
• The young twigs and leaves of Actinidia polygma (mentioned above) have been used for centuries in Asia to tranquillize lions and tigers in zoos (le Strange 1977).
• Catnip growing near houses has long had a reputation for repelling rats, no doubt because the plants attract cats.
• Catnip, itself sometimes referred to as cat-marihuana, was used in the 1960's as a substitute for marihuana, apparently producing visual and auditory hallucinations when smoked (Grognet 1990). Tyler (1993) castes doubt on the mind-altering properties in humans alleged for catnip.
• The physicians who first described the drug use of catnip by people, published their findings in The Journal of the American Medical Association in 1969 with a drawing of catnip labelled as marihuana and vice-versa. Over 1600 letters were received by the editor pointing out the mistake (Tyler 1993).
• Cats tend to leave catnip plants alone, unless the plants are bruised and so release the attractive chemicals. There is an old saying about catnip (Grieve 1931):
  

  If you set it, the cats will eat it,

  If you sow it, the cats don't know it

  The rationale is that catnip grown from seed will not be bruised, while transplanted (i.e. "set") plants will usually be bruised during planting.
• Catnip has been shown to increase the frequency of catnaps in chicks (Sherry and Koontz 1979).
• Mustard oil (see Brassica in this book) and asafetida (the fetid gum resin of various Oriental species of Ferula (of the carrot family), formerly used in medicine) are thought to repel cats (Duke 1985).

Fig. 257. "Catnip high," prepared by B. Brookes.

Problems and Potential

The culinary use of catnip is too restricted to be of economic interset. The plant is, however, widely cultivated in Eurasia, as a source of oil used for various purposes, which would suggest that there may be some economic potential for the plant as a North American crop. As with many of the other herbs discussed in this book, the strongly established foreign crop limits possibilities for the U.S. and Canada.

Selected References

Simon et al. (1984); Ferguson et al. (1988); Tucker and Tucker (1988); Grognet (1990).