How to Grow Catnip From Seed

Catnip is a hardy perennial, so plant it once and enjoy it for years. Direct-sow the seeds outdoors after your last spring frost, once the soil has warmed to around 60 to 70F, or start them indoors about four to six weeks earlier for a head start. In mild-winter zones you can also sow in early fall. Because catnip self-sows, a single spring planting often gives you volunteer seedlings the following year.

Catnip seeds have a hard coat and germinate best after a cold spell, so chill them first: freeze the seeds overnight and soak them for 24 hours, or keep them on a damp paper towel in the refrigerator for three to four weeks. Sow the seeds shallowly, about an eighth of an inch deep, and barely cover them, since they need a little light to sprout. Keep the soil evenly moist at 60 to 70F and seedlings appear in about 7 to 14 days. Thin or space the plants 18 to 24 inches apart in full sun to part shade and well-drained soil, because each one grows into a bushy clump two to three feet tall.

Catnip is famously easy and forgiving. Water young plants regularly, then ease off once they are established, as catnip shrugs off heat and dry spells and actually prefers lean, well-drained soil to rich ground. Pinch and harvest the tips often to keep growth bushy rather than leggy, and shear the whole plant back by about a third after its first flush of flowers to spark fresh growth. It rarely suffers serious pests. If neighborhood cats roll on young seedlings, a low cage or a few twiggy branches laid over the bed protects them until they toughen up. Catnip is a tough perennial across USDA zones 3 to 9, so it survives cold Midwest and Northeast winters and comes back each spring; in hot, dry regions like the Southwest it thrives on lean soil and little water, and in much of the country it self-seeds readily and can naturalize, so shear off spent flowers if you would rather it not spread.

Catnip earns its place in the garden by drawing in bees and other pollinators when it flowers, while its strong scent helps confuse pests looking for a meal. These four make especially good companions, and you can add any of them in one click:

You can snip sprigs of catnip any time once the plant is established, but the leaves are most aromatic just as the flower buds begin to open, when the fragrant oils peak. Cut the leafy top growth in the morning after the dew dries, taking up to a third of the plant at once so it bounces back. Use it fresh, or tie small bunches and hang them upside down in a warm, airy, shady spot for a week or two, then crumble the dried leaves into an airtight jar.

Catnip is best known as a treat for cats, who love to sniff, roll in, and play with both the fresh plant and dried leaves stuffed into homemade toys. In the garden its summer flowers are a magnet for bees and other pollinators, making it a cheerful, low-effort perennial for a herb bed or border. The mint-family leaves are also a traditional herbal tea ingredient, brewed for a mild, minty, lemony cup.

• Poor or slow germination: chill the seeds first (freeze overnight and soak, or refrigerate on a damp towel for a few weeks), sow them shallow, and keep the soil warm and evenly moist.
• Flopping, leggy plants: pinch the tips often and shear the plant back by a third after flowering to keep it compact and bushy.
• Cats flattening seedlings: protect young plants with a low cage or a few twiggy branches until the stems toughen up.
• Spreading where you do not want it: deadhead the flowers before they set seed, or grow catnip in a container to contain the roots.