Chewed leaves and blooms, dieback, holes in stems, and damage to twigs or bark indicate a beetle invasion in your landscape. Although most insects are beneficial or harmless, the 1% classified as pests can wreak havoc in your garden. Gardeners have long used catnip (Nepeta cataria) as an insect repellent, but it was only in 1941 that scientists identified the compound responsible for both repelling insects and attracting cats. Nepelalactone, an iridoid, is as effective as DEET in controlling certain insects, including beetles, by triggering a pain receptor. The plant deters both benign and harmful beetles, making it ideal for an integrated pest management system that uses multiple strategies to manage insect infestations.
Asian lady beetles, an orange insect with spots, are one of the benign insects repelled by nepetalactone. They help keep your garden pest-free by consuming aphids and other soft-bodied insects, such as scale insects, but can become a nuisance indoors. To prevent them from entering your home while allowing them to continue their work outside, grow catnip in containers if you have a sunny spot like a windowsill. If you have cats that might be drawn to the plant, consider growing it in a hanging basket near a sunny window. For those without cats or who don’t want them attracted, using catnip essential oil in a diffuser is an alternative.
Growing Catnip in the Garden
Catnip, a mint family member, thrives in zones 3 through 9. This herbaceous perennial, native to Asia and Europe, has naturalized in the U.S., meaning it has established itself outside its native range and can reproduce independently. Catnip is easy to cultivate due to its adaptability to various growing conditions. It flourishes in well-drained soil with full sun or partial shade. In hot climates, provide some afternoon shade. It is drought-tolerant, withstands air pollution, is pest and disease-resistant, and deer avoid it. Mature plants form mounds and can grow up to 3 feet tall, with blue flowers on spikes 1 to 6 inches tall blooming in spring and continuing through summer. Prune spent flowers to encourage new blooms.
Catnip attracts pollinators like bees and butterflies, and its foliage feeds moth larvae. The plant is low in toxicity, usually causing only diarrhea or vomiting in cats that overindulge. Like other mints, catnip can overrun a garden if not controlled. Control measures include mowing the plants to the ground, digging them up, or dividing and replanting them elsewhere. Remember that catnip will regrow unless you remove all plant parts, including underground rhizomes, or use an herbicide to kill it.
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