Nepeta cataria is a short-lived perennial, herbaceous plant that grows to be 50–100 cm tall and wide, which blooms from late spring through 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.
Nepeta cataria is cultivated as an ornamental plant for use in gardens. It is also grown for its attractant qualities to house cats and butterflies. The plant is drought-tolerant. It can be a repellent for certain insects, including aphids and squash bugs. Catnip is best grown in full sunlight and grows as a loosely branching, low perennial. Varieties include Nepeta cataria var. citriodora (or N. cataria subsp. citriodora), or “lemon catnip”.
The plant terpenoid nepetalactone is the main chemical constituent of the essential oil of Nepeta cataria. Nepetalactone can be extracted from catnip by steam distillation. The compound iridodial, extracted from catnip oil, has been found to attract lacewings that eat aphids and mites.
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.