How to Grow Catnip from Seed (Nepeta cataria)

Catnip has a reputation problem. Most people know it as the herb that turns a dignified cat into a rolling, chirping lunatic, and stop there. Gardeners who grow it know the other half of the story: Nepeta cataria is a tough, drought-tolerant perennial from the mint family that flowers for months, feeds bees from June until the first frosts, and asks almost nothing in return. It is one of the easiest herbs to raise from seed — genuinely a sow-it-and-forget-it plant — and one packet will keep a household of cats supplied for years. This guide covers the whole cycle: when to sow, how to germinate it reliably, how to keep it from flopping, and how to harvest and dry the leaves so they keep their punch.

• Botanical name Nepeta cataria — hardy herbaceous perennial, Lamiaceae (mint family)
• Sow March–May indoors, or April–June and again in early September direct outdoors
• Flowers white with faint purple speckling, June–September on 60–100 cm stems
• Position full sun, free-draining soil — thrives on neglect and poor ground

Why grow catnip

The obvious reason is the cats. The active compound is nepetalactone, a volatile oil held in the leaves and stems, and roughly two-thirds of cats carry the inherited receptor that responds to it. Those that do get ten to fifteen minutes of rolling, rubbing and blissful nonsense, followed by an hour or so of immunity before it works again. Kittens under about six months usually show no response at all.

The less obvious reason is the bees. Catnip flowers from midsummer into autumn, exactly when many border plants have finished, and the small tubular blooms are worked constantly by honeybees, bumblebees and hoverflies. If you are putting together a planting for pollinators, it deserves a place near the front — our guide to creating a pollinator garden for bees and butterflies shows how to build a season of nectar around plants like it. Catnip is also a useful culinary and medicinal herb in its own right: the leaves make a mild, minty, faintly lemony tea that has been drunk as a calming infusion for centuries. New to growing herbs? Start with our complete guide to growing herbs from seed.

When to sow catnip

Catnip is not fussy about timing. The main window is spring: sow indoors from March to May for the earliest, strongest plants, or direct outdoors from late April once the soil has warmed to around 15 °C. There is a second, quieter window in late summer — a sowing in the first half of September will germinate in warm soil, make a small rosette before winter and romp away the following spring, much like the hardy annuals in our guide to autumn sowing.

Expect leafy plants in year one and the full flowering display from year two onwards. Reading this in mid-August? A September sowing is still comfortably within reach, and there is plenty else that can go in now — see what to sow in August, or check the timings for every herb in our herb sowing calendar.

How to sow catnip, step by step

1. Chill the seed for a week (optional but worth it) Catnip germinates without any treatment, but a week in the fridge in a barely damp bag lifts and evens out the germination rate noticeably. The reasoning is set out in our germination guide.
2. Sow on the surface, barely covered The seed is small and needs light. Press it onto moist seed compost in modules and dust with no more than 2–3 mm of vermiculite. Hold at 18–21 °C — our indoor seed starting guide covers the kit.
3. Expect seedlings in 7–14 days Keep just moist, water from below and ventilate daily so the surface dries between waterings — that alone prevents most damping off. Nothing showing after three weeks? Work through our germination troubleshooting guide.
4. Pot on, harden off, plant out Move to 9 cm pots at the four-leaf stage, harden off over a week and plant 45 cm apart. Space matters: crowded catnip sulks and mildews.
5. Or sow direct into warm soil Rake a sunny patch to a fine tilth following our soil preparation guide, sow thinly on the surface, firm gently and keep damp until up. The method is in our direct sowing guide. Protect the seedlings — see the mistakes section below.

Catnip or catmint? Two different plants

These names are used interchangeably in garden centres, which causes endless confusion. They are related but not the same, and if you want a reaction from your cat the distinction matters.

In short: plant catnip for the cat and the store cupboard, catmint for the border. Many gardens have room for both, and both sit happily alongside other members of the family such as mint, lemon balm and valerian.

Caring for catnip

Catnip does best when you leave it alone. Full sun and free-draining soil are the only real requirements; it grows perfectly well on thin, stony, impoverished ground and actually produces more aromatic oil there than in rich, moist beds. Water new plants through their first summer using the deep, infrequent approach in our watering guide, then largely stop — established clumps are markedly drought-tolerant. Skip the fertiliser entirely: as our guide to feeding and fertilising explains, nitrogen on an aromatic herb buys you soft, floppy, less fragrant growth.

Two jobs are worth doing. First, cut the whole plant back by about a third after the first flush of flowers — it prevents the sprawl catnip is prone to and brings a second flowering in late summer. Second, decide about self-seeding. Catnip seeds itself freely, and while it is not the thug that running mint is (it clumps rather than runs), a happy plant will scatter offspring across a bed. If you want it contained, cut the flower stems before the seed ripens; if you want more plants, let one or two stems shed and lift the seedlings in spring. A mulch around the crown keeps the ground clean and makes volunteers easy to spot. Otherwise it is untroubled by most problems in our guide to garden pests — deer and rabbits ignore it, and the plant is often used as a companion planting deterrent against aphids and flea beetles near brassicas and squash. Cut the dead top growth to the ground in late autumn and it will return in spring.

Harvesting and drying catnip

Cut for maximum potency just as the flower buds open, on a dry morning after the dew has lifted — this is when the oil content peaks. Take whole stems, no more than a third of the plant at a time, using the general principles in our guide to harvesting and storing produce. You can crop two or three times a season.

Dry catnip in the dark: bundle five or six stems, tie the base and hang them upside down somewhere warm, airy and shaded for one to two weeks, until the leaves crumble at a touch. Light is what degrades nepetalactone, so a sunny windowsill will give you dried leaves with none of the effect. Strip the leaves and flowers from the stems, crumble them coarsely and store in an airtight jar in a dark cupboard. Kept that way the potency holds for six to twelve months; a jar in the freezer keeps it noticeably longer. Want your own seed for next year? Let a few heads ripen to brown and collect them with the methods in our guide to seed saving, then keep them cool and labelled following our seed storage guide.

Common catnip mistakes

• Burying the seed — it needs light to germinate. A dusting of vermiculite is plenty; 1 cm of compost is too much.
• Leaving seedlings unprotected — cats will roll on and destroy young plants. Cover new sowings with a wire cloche or a few crossed twigs until the plant is established and tough enough to take it.
• Feeding and watering it like a vegetable — rich, damp conditions give lush leaves with weak aroma. Poor and dry is what you want.
• Planting it too close — crowded plants get powdery mildew. Allow 45 cm and let the air move.
• Drying in sunlight — the fastest way to end up with attractive dried leaves your cat completely ignores.
• Letting every stem set seed — unless you want a catnip meadow, cut most flower stems before the seed ripens.

Frequently asked questions

Is catnip safe for cats?
Yes. It is non-addictive and non-toxic, and cats self-regulate — the response fades after ten to fifteen minutes and cannot be triggered again for an hour or more. Very large quantities eaten fresh can cause mild digestive upset, so offer dried leaves in modest amounts. Around a third of cats have no reaction at all, which is genetic rather than anything you have done wrong.

Does catnip come back every year?
It does. Nepeta cataria is a hardy herbaceous perennial: the top growth dies back after frost and fresh shoots appear from the crown each spring. Individual plants are relatively short-lived, often three to five years, but self-sown seedlings usually replace them without any help.

Can I grow catnip in a pot?
Yes, and it is a good way to keep it away from roaming cats and stop it self-seeding. Use a 25–30 cm pot with free-draining compost and plenty of grit, put it in full sun, and water only when the top few centimetres have dried out.

Can people drink catnip tea?
Yes — catnip has a long history as a mild herbal infusion, with a gentle minty, lemony flavour. Use a teaspoon of dried leaves per cup and steep for five minutes. As with any herb, it is sensible to check with a doctor if you are pregnant, breastfeeding or taking medication.

Few plants give back this much for this little effort. Give catnip a sunny, stony corner, cut it back after flowering, and it will hand you fragrant leaves for the jar, months of flowers for the bees and a very contented cat. Browse our herb seeds, the perennial herbs that come back every year, our organic herbs and edible flowers, see what else can go in this month in sow in August, browse all our seeds, or dig into the rest of our growing guides.