Nepeta cataria is a herbaceous perennial plant commonly cultivated as a garden herb called catnip. It is commonly used to flavor herbal teas, juices, and soups. Catnip is widely known for its peculiar behavioral effect on cats, so people commonly use it as a toy stuffer or treat for their feline pets.
I. Appearance and Characteristics
Nepeta cataria, commonly known as catnip, catswort, catwort, and catmint, is a species of the genus Nepeta in the family Lamiaceae, native to southern and eastern Europe, the Middle East, Central Asia, and parts of China. It is widely naturalized in northern Europe, New Zealand, and North America. The common name catmint can also refer to the genus as a whole.
The names catnip and catmint are derived from the intense attraction about two-thirds of cats have toward the plant (alternatives exist, such as valerian root and leaves). Catnip is also an ingredient in some herbal teas (or tisanes), and is valued for its sedative and relaxant properties.
Nepeta cataria was one of the many species described by Linnaeus in 1753 in his landmark work Species Plantarum. He had previously described it in 1738 as Nepeta floribus interrupte spicatis pedunculatis (meaning ‘Nepeta with flowers in a stalked, interrupted spike’), before the commencement of Linnaean taxonomy.
Nepeta cataria is a short-lived perennial, herbaceous plant that grows to be 50–100 cm (20–40 in) tall and wide, and that blooms from late spring to autumn. In appearance, N. cataria resembles a typical member of the mint family of plants, featuring brown-green foliage with the characteristic square stem of the plant family Lamiaceae. The coarse-toothed leaves are triangular to elliptical in shape. The small, bilabiate flowers of N. cataria are fragrant and are either pink in colour or white with fine spots of pale purple.
II. Types of Catnip
Besides Nepeta cataria, there are several plants that go by the name catnip, including:
- Nepeta citriodora: Known as lemon catnip, this plant grows slightly smaller than Nepeta cataria and has a lemony fragrance.
- Nepeta camphorata: Commonly referred to as camphor catnip, this plant remains under 2 feet tall and wide.
- Nepeta parnassica: Known as Greek catnip, this plant also remains smaller than 2 feet tall and wide and bears light pink flowers.
III. How to Grow and Care
Sunlight
Catnip needs lots of sunlight to grow–approximately six hours per day. In extreme heat, it can have a difficult time; gardeners who live in a hot climate should plant catnip in an area that receives some shade in the afternoon. Indoor catnip plants grow best in a sunny window.
Temperature and Humidity
Catnip prefers temperatures between 55 and 85 degrees Fahrenheit. The plant tends to struggle in hot, humid climates. Especially in high humidity, make sure there is good air circulation around the plant to help prevent fungal growth.
Watering
Catnip is a very drought-tolerant plant, and sitting in waterlogged soil can kill it. Keep the soil of seedlings lightly moist but not soggy. Mature plants likely won’t need watering unless you have a prolonged period of drought. If the foliage is wilting, give your catnip a deep watering.
Soil
These plants aren’t fussy about their soil as long as they have good drainage. They can tolerate poor, rocky, and dry soils. A well-draining sandy or loamy soil is best with a slightly acidic to slightly alkaline soil pH (6.1 to 7.8).
Fertilizing
Mix some compost into the soil at the time of planting to give your catnip a boost. After that, catnip typically won’t need additional feeding. But if you have very poor soil, you can use an all-purpose liquid plant food (for the amount to use, follow product label instructions) or a layer of compost each spring.
Planting Instructions
Catnip thrives in well-drained soil and needs plenty of sunlight. In hot climates, catnip does best with partial shade in the afternoon. You can plant catnip directly into the ground or in a raised bed, but make sure to provide some constraints on this plant. It is part of the mint family and can quickly take over your garden. Catnip grows in USDA zones 3 through 9.
The ideal time to plant catnip is in the spring after the last frost in your region. Buy a starter plant at your local nursery or grow catnip from seed.
Set a nursery-grown plant in a prepared garden bed at the same level it grew in its container. Space multiple plants 18 to 24 inches apart, watering them lightly and regularly until they are established.
Sow seeds indoors approximately six weeks before the expected last frost date. Transplant the seedlings 18 to 24 inches apart in the garden so each plant has sufficient space to grow. You can also sow the seeds directly in a prepared garden bed when the weather starts to warm and cover them lightly with soil. A light frost won’t damage them before they germinate, but a late frost might.
Catnip grown in containers indoors can be planted or sown at any time of year.
Pruning
Pruning is a good idea to keep catnip from spreading throughout the garden and hindering the growth of other plants. One way to prevent this plant from spreading is to cut back new growth that sprouts from underground runners. For bushier growth, cut back stems on young plants.
Propagation
Catnip spreads easily—too easily, according to some gardeners. However, if you want to propagate it, use stem cuttings.
Trim a 4- to 6-inch piece of a stem directly under a leaf node. Remove the leaves from the bottom half of the cutting. Put the cutting into a jar of water or place it in a pot filled with moist soilless potting mix. Replace the water every day or ensure the potting mix is moist. When there is new leaf growth, the cutting has rooted and can be transplanted.
Potting and Repotting
Container-grown catnip grows best in an 8- to 10-inch container that provides excellent drainage. Also, add some perlite to high-quality potting soil to improve drainage, and only water when the soil surface is dry. Position the plant in a sunny window. It will grow tall and leggy if it doesn’t get enough light. If that happens, pinch back the lanky stems. Repot the catnip annually with fresh planting medium.
Overwintering
Catnip typically does fine over the winter within its growing zones. Cut back any tender new growth in the fall, so cold weather doesn’t damage it and weaken the plant. And be sure to stop fertilizing in the fall to avoid promoting new growth. Don’t water the plant over winter. Wet soil in the wintertime can be fatal.
Pests and Diseases
You usually don’t have to worry about pests when growing catnip. It’s worth checking the leaves for spider mites occasionally. Make sure never to let catnip sit in water, as this can lead to root rot and cause the plant to die.
Cats that rub themselves on young catnip plants can damage the leaves and stems. Protect catnip plants with short bamboo sticks embedded in the ground near the plants.
IV. Uses and Benefits
- Ornamental uses
Catnip (Nepeta cataria) is intensely aromatic, has interesting leaves, and pretty white flowers. It is best to grow this plant close to patios, or beside paths and walkways where its unique aroma can be appreciated. Catnip grows well with vegetables like radishes, beetroot, pumpkins, and tomatoes. It is a common bedding and border plant in Mediterranean, informal, and cottage gardens.
- Medicinal uses
Catnip has a history of use in traditional medicine for a variety of ailments such as stomach cramps, indigestion, fevers, hives, and nervous conditions. The plant has been consumed as a tisane, juice, tincture, infusion, or poultice, and has also been smoked. However, its medicinal use has fallen out of favor with the development of modern medicine.
- Biological control
The iridoid that is deposited on cats who have rubbed themselves against the plants and scratched the surfaces of catnip and silver vine (Actinidia polygama) leaves repels mosquitoes. The compound iridodial, an iridoid extracted from catnip oil, has been found to attract lacewings that eat aphids and mites.
- As an insect repellent
Nepetalactone is a mosquito and fly repellent. Oil isolated from catnip by steam distillation is a repellent against insects, in particular mosquitoes, cockroaches, and termites. Research suggests that, while a more effective spatial repellant than DEET, when compared with SS220 or DEET, it is not so effective as a repellent as it is when used on the skin of humans.
- Effect on felines
Catnip contains the feline attractant nepetalactone. N. cataria (and some other species within the genus Nepeta) are known for their behavioral effects on the cat family, not only on domestic cats, but also other species. Several tests showed that leopards, cougars, servals, and lynxes often reacted strongly to catnip in a manner similar to domestic cats. Lions and tigers may react strongly as well, but they do not react consistently in the same fashion.
With domestic cats, N. cataria is used as a recreational substance for the enjoyment of pet cats, and catnip and catnip-laced products designed for use with domesticated cats are available to consumers. Common behaviors cats display when they sense the bruised leaves or stems of catnip are rubbing on the plant, rolling on the ground, pawing at it, licking it, and chewing it. Consuming much of the plant is followed by drooling, sleepiness, anxiety, leaping about, and purring. Some growl, meow, scratch, or bite at the hand holding it. The main response period after exposure is generally between 5 and 15 minutes, after which olfactory fatigue usually sets in. However, about one-third of cats are not affected by catnip. The behavior is hereditary.
Cats detect nepetalactone through their olfactory epithelium, not through their vomeronasal organ. At the olfactory epithelium, the nepetalactone binds to one or more olfactory receptors.
A 1962 pedigree analysis of 26 cats in a Siamese breeding colony suggested that the catnip response was caused by a Mendelian-dominant gene. A 2011 pedigree analysis of 210 cats in two breeding colonies (taking into account measurement error by repeated testing) showed no evidence for Mendelian patterns of inheritance but demonstrated heritabilities for catnip response behavior, indicating a polygenic liability threshold model.
A study published in January 2021 suggests that felines are specifically attracted to the iridoids nepetalactone and nepetalactol, present in catnip and silver vine, respectively.
Felines not affected by catnip
Cats younger than six months might not exhibit behavioral change to catnip. Up to a third of cats are genetically immune to catnip effects but may respond to and enjoy catnip alternatives such as valerian (Valeriana officinalis) root and leaves; silver vine or matatabi (Actinidia polygama), popular in Asia; and Tatarian honeysuckle (Lonicera tatarica) wood.
V. Harvesting and Storage
Harvest catnip when it’s in bloom. Late morning is a good time to harvest after the dew has dried but before the day heats up and potentially causes the plant to wilt. Cut off entire stems or even the whole plant if you wish. Catnip plants are good for making actual catnip for your cat’s enjoyment. Catnip is used dried in sachets, teas, cat toys, and more. Hang the stems upside-down for drying in a dark, dry, well-ventilated space as soon as possible after harvesting. Once they’ve dried out, which usually takes two to three weeks, the leaves and flowers can be crumbled for use.
