How to grow catnip
Overview
Catnip is a hardy herbaceous perennial from the mint family, grown for its aromatic foliage and small white or lavender flowers. It is a vigorous filler plant that attracts cats and beneficial insects, and thrives with minimal care.
Varieties
- Nepeta cataria — The classic catnip, with grey-green leaves and white flowers, most attractive to cats.
- Nepeta cataria 'Citriodora' — Lemon-scented catnip, popular for its citrus aroma and slightly less invasive habit.
Soil Preparation
Catnip prefers neutral to slightly alkaline soil (pH 6.5–7.5) with sharp drainage. Add lime if soil is acidic. Enrich with compost before planting, but avoid heavy clay or waterlogged sites.
Growing Guide
Plant catnip in full sun with well-drained, moderately fertile soil. Space plants 45–60 cm apart to allow for spreading. Sow seed directly in spring or early summer at 3 mm depth, or transplant seedlings after frost. Water sparingly once established; overwatering causes root rot. Pinch out tips early to encourage bushiness.
Sowing
Sow seeds 3 mm deep in seed trays or direct in garden beds. Germination takes 7–14 days at 18–22°C. Transplant when 10 cm tall. Catnip self-seeds readily, so deadhead if you want to control spread.
Care
Feed lightly with a balanced liquid fertiliser once in early spring. Cut plants back hard after flowering to promote fresh growth and prevent self-seeding. Divide clumps every 2–3 years to maintain vigour and prevent woody centres.
Companion Planting
Catnip repels aphids, flea beetles, and squash bugs, making it a good companion for brassicas, cucurbits, and roses. Avoid planting near lavender or sage, as they prefer drier conditions than catnip.
Common Pests & Risks
Whitefly can be a problem in warm, humid conditions; control with neem oil or reflective mulch. Catnip is rarely bothered by other pests due to its strong aroma. Powdery mildew may occur in poor air circulation—space plants well.
Harvesting
Harvest leaves and flower tops anytime from late spring to early autumn, just before flowers fully open for strongest scent. Cut stems at the base and dry in a shady, airy spot. Regular harvesting keeps plants compact and productive.
Troubleshooting
Yellow leaves: overwatering or poor drainage—reduce water and improve soil. Leggy growth: insufficient light—move to full sun. Powdery mildew: crowded plants—increase spacing and prune. Poor scent: low heat or old leaves—harvest young leaves in warm weather. Cat not interested: some cats lack the gene—try a different variety.