Nepeta cataria Seeds | Catnip
LATIN NAME: Nepeta cataria
COMMON NAME: Catnip
Plant Profile
Steam distillation of the flowering tops yields an oil whose dominant components are the iridoids nepetalactone, both cis,trans and trans,cis forms, together with smaller amounts of citronellol, geraniol, and nerol. Because nepetalactone is labile, distillation conditions change the ratio, which is why oils from different harvests smell differently even from the same field.
Selected lemon and ornamental forms are multiplied by stem cutting or by micropropagation on a cytokinin-rich medium to keep scent and habit uniform, since open-pollinated seed produces variable plants.
Shear the plant to a few centimetres after the first flowering to push fresh leafy growth and reduce self-sown seedlings. The crown is hardy in most mild gardens; a thin gravel mulch over the base keeps it dry through cold, wet months.
Science & Biotechnology
Rub a leaf of catnip between your fingers and the reaction from a nearby cat can be theatrical, with rolling, chin-rubbing, and drooling following within seconds for many animals. The trigger is nepetalactone, an iridoid monoterpene that makes up a large fraction of the leaf’s essential oil. Cats detect it not through the nose but through the vomeronasal organ, Jacobson’s organ, on the roof of the mouth, which is why a cat will often open its mouth slightly and wrinkle the lip, the flehmen response, after sniffing the plant. Not every cat reacts; the trait runs in families, and young kittens and elderly animals often ignore it.
Nepeta cataria is a loosely branching perennial mint with square stems that reach 50 to 100 cm. The heart-shaped, coarsely toothed leaves are green above and thickly covered with white down underneath, and the whole plant is dotted with glandular hairs that store the oil. Flowers sit in dense whorls, verticillasters, at the stem tips, each small, two-lipped, and white with faint purple dots.
The genus name Nepeta comes from Nepi, a town in the Etruscan region of Italy, where the plant grew abundantly and was used in local cookery. The species has been carried by people for so long that its original range is now blurred; it grows wild from the Balkans to the British hedgerows and has naturalized across much of North America.
Gardeners confuse catnip with the showier perennial catmints such as Nepeta ‘Six Hills Giant’ and with lemon catnip, which carries a citrus note from added citral. True catnip has the downy white leaf underside and the purple-spotted white flower; the ornamental catmints are bluer in bloom and lack the strong feline effect.
The same compound that excites cats repels insects. Laboratory assays have shown catnip oil to drive off mosquitoes and other biting flies, and nepetalactone has been compared with synthetic repellents in cage tests. The effect is being studied for crop protection and for treated fabrics, though field performance depends on formulation and dose.
Uses & Benefits
Dried leaf is stuffed into fabric toys or sprinkled on scratching posts; a small handful refreshes a tired toy. Grow a patch apart from the ornamental border if you do not want visiting cats flattening it.
The leaves have a long place in herbal infusions, lightly steeped like mint. The flavor is musky and green; a teaspoon of dried leaf to a cup of just-boiled water, steeped briefly, is the usual preparation.
Catnip’s loose habit suits the front of a cottage garden or a gap in a herb knot. It pairs well with yarrow, oregano, and lavender, and the bloom draws bees and butterflies.
Growing from Seed
Press seed onto a fine, open mix of compost and sand and leave it uncovered, since light improves emergence. Keep the surface damp with a fine mist and shield the tray from harsh sun until seedlings stand.
When seedlings reach the second pair of true leaves, move them to individual pots. Transplant to the garden at 30 to 45 cm spacing once plants are 10 to 15 cm tall; closer spacing traps humidity and invites mildew on the felted leaves.
Our Take
Catnip is the one herb I plant where the cat cannot reach it, because a happy cat will wreck a neat clump overnight. Grow it for the bees if not for the cat, and dry a jar of leaf for winter tea.
Closely related reading: Lemon Catnip, Schizonepeta, and Hyssop.
Related Reading
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