Catnip is a perennial herb in the mint family, grown for its aromatic foliage that attracts cats and pollinators. The leaves contain nepetalactone, the compound that triggers a response in cats. Gardeners also use it for herbal teas and as a deterrent for some garden pests.
Like other mints, catnip spreads aggressively through seed and root runners. Plant it in a container or buried barrier to control spread. Cut plants back after the first flowering to encourage a second flush and prevent self-seeding.
Powdery mildew
White or grey powdery coating on leaves — usually starting on older growth in humid conditions or when nights cool.
Improve air circulation by thinning plants. Apply neem oil or potassium bicarbonate spray at first sign. Avoid overhead watering.
Spider Mites
Fine stippling or bronzing on leaves, faint webbing on undersides, foliage drying out during hot, dry weather.
Spray foliage with a strong jet of water to dislodge mites. Apply insecticidal soap or horticultural oil to leaf undersides; repeat every 5–7 days as needed.
Aphids
Clusters of small soft insects on new growth and flower buds.
Knock off with a strong jet of water. Ladybirds and lacewings are natural predators. Insecticidal soap as last resort.
Mint Rust
Small orange or rust-colored pustules on the undersides of leaves, followed by yellowing, distortion, and leaf drop. Stems may show swelling.
Remove and destroy infected foliage. Avoid overhead watering and improve air circulation. Cut plants to the ground and dispose of debris in severe cases. Do not compost infected material.