Catnip (Nepeta cataria) is a common herb that thrives in much of North America and is very easy to grow. While you've probably heard that catnip makes cats tipsy, you might not know that this effect is an inherited trait and it does not affect all cats.
Catnip grows to a height of 3 to 4 feet and has featherlike, light green foliage and small clusters of lavender flowers that grow on spikes. A member of the mint family, catnip is also used in food and herbal remedies. For example, tea made from the leaves and flowers of Nepeta cataria is said to relieve coughs. The oil extracted from catnip plants is even used in natural mosquito repellents.
Catnip plants have naturalized in various parts of North America, and even where they are not perennial, they will likely reseed. In fact, many gardeners find catnip to be too weedy and too aggressive to grow it in their landscapes. This herbaceous perennial can be planted in spring or fall. It is a fast grower and can reach 2 to 3 feet in height in a single season.
If you're planning to grow catnip, for your cat or yourself, keep in mind that there are different types of catnip and that all common types are invasive. This means they can take over your garden—even if they don't take over your cat's mind.
|Botanical Name||Nepeta cataria|
|Common Name||Catnip, catmint|
|Plant Type||Herbaceous perennial herb|
|Mature Size||2 to 3 feet tall and wide|
|Sun Exposure||Full sun|
|Soil Type||Moderately rich loam or sandy, well-drained|
|Soil pH||Acidic to alkaline (6.1 to 7.8)|
|Bloom Time||Summer and fall|
|Flower Color||White, lavender|
|Hardiness Zones||3 to 9 (USDA)|
|Native Area||Eurasia; widely naturalized elsewhere|
|Toxicity||Toxic to cats|
How to Plant Catnip
Catnip can be planted in your garden in spring or fall, from seed or plants. It will sprout in two to three weeks if started from seed. Cutting back the plants after the first bloom set will allow enough time for it to completely regrow and bloom again.
Some species of Nepeta will spread out of control unless you take measures to keep them from doing so. To contain and shape catnip plants, pinch them often while they are growing to obtain dense, well-shaped plants. The plants will also reseed all over your property if you let them and you will have new plants springing up in unexpected places for years to come. To prevent the plant from blooming, simply pinch off the top of the plant when flowers start to form.
To avoid damage from unwelcome neighborhood cats, consider protecting your catnip with some type of enclosure. Insects and rodents are not a problem, and catnip does not tend to suffer diseases.
Catnip plants do best in full sun to partial shade and are drought-tolerant ground covers, making them a good choice for sunny, dry areas where many other plants would struggle.
Like so many herbs, this perennial thrives in poor soil that is well-drained. Catnip plants are not very fussy about the ground in which they grow, as long as their roots are not constantly sitting in water.
Water catnip plants regularly, but be careful not to overwater. Allow the soil to go almost dry between waterings, then soak thoroughly.
Temperature and Humidity
Plant catnip in soil that registers a minimum of 60 degrees Fahrenheit. It will grow best in daily temperatures between 55 and 85 degrees Fahrenheit. In hot, humid climates, it may need some afternoon shade.
You do not need to feed catnip.
Is Catnip Toxic?
Most people associate catnip with its psychoactive effect on cats. The effect occurs when the leaves are eaten or when the plant's fragrance is inhaled by cats. In fact, simply smelling catnip is often enough to cause cats to react to it, which is why you sometimes see them rolling in it. The resulting "drug trip" is a reaction to the chemical nepetalactone. An inherited trait, only some cats have nepetalactone reactions. Likewise, it's possible for cats to have adverse reactions to catnip, possibly causing diarrhea or vomiting. This is why the American Society for the Prevention of Cruelty to Animals (ASPCA) lists catnip as a toxic plant for cats.
Catnip vs. Catmint
Plant taxonomy classifies catnip plants as Nepeta cataria. Note that the common name "catmint" is preferred in the U.K. It may be tempting to use the two names interchangeably, but in the U.S., "catmint" typically refers to one of the ornamental relatives of N. cataria. Fewer cats are attracted to ornamental types. In any case, look for the scientific or botanical name when shopping for plants to be sure you get the right type of catnip.
- Nepeta cataria: Preferred by cats; deer-resistant but attracts butterflies
- Nepeta mussinii: Attractive ornamental plant that grows to about 1 foot tall; often used as a ground cover and also attracts butterflies
- Nepeta x faassenii: Produces oval, intricately veined, gray-green leaves and abundant lavender flowers, from spring through autumn; not as invasive as other Nepeta species
Harvest catnip upon flowering, on a dry, sunny day. Late morning is a good time to harvest after the dew has dried but before the day heats up. Cut off the whole plant at the base, and hang it upside down, as soon as possible, in a dark, dry, well-ventilated place, such as an attic.
Store dried leaves, stems, and flowers in freezer bags to preserve the potency of the oil inside them. These steps help minimize the loss of the oil, which is the stuff that makes your cat go wild.
How to Grow Catnip From Seed
Catnip seeds have tough coats, and you'll improve the chance of success by first stratifying the seeds. Place the seeds in a plastic bag and keep them in the freezer for a month. Take them out and let them thaw, then freeze them again for another month. Prior to planting, thaw the seeds in warm water overnight.
Sow the stratified seeds in pots one to two months before the last spring frost. Plant them about 1/4 inch deep in seed-starting mix, and set them in front of a sunny window. They should sprout in two to three weeks. Harden off the seedlings before planting them in the garden, spacing them 18 to 20 inches apart. You can also keep them in pots to grow indoors.
Lichman, Benjamin R., et al. The Evolutionary Origins of the Cat Attractant Nepetalactone in Catnip. Science Advances, vol. 6, no. 20, 2020, doi:10.1126/sciadv.aba0721
Nepeta Cataria. Missouri Botanical Garden