How to grow a catnip plant

Catnip is an excellent garden plant, blooming through much of summer. Nepeta cataria forms a clump of slender branching stems clothed with toothed grey-green leaves, up to 90cm high and 60cm wide. The flower clusters, made up of many tiny blooms, are violet spotted with white and are borne through summer. The blooms are rich in nectar and entice bees along with a wide selection of pollinating insects. Although this species is decorative, other species and varieties of catmint (Nepeta) have greater ornamental value.

How to grow catnip

Catnip plants are available to buy and plant at any time of year, in a sunny site and well-drained soil, or a large pot. Alternatively grow your own from seed, sowing from spring to autumn. Cut back dead stems during the dormant period and before new shoots start to appear in mid-spring.

Where to grow catnip

Catnip plant needs a free-draining soil and grows best when given plenty of sun. Plant at the edge of a border, in a raised bed, or a large pot. Once established, catnip is tolerant of drought.

How to plant catnip

Plant pot-grown catnip plants at any time of year, with autumn or spring being ideal times to plant. Grow in soil that is poor to moderately fertile, without additional manure or fertiliser. If the soil is heavy and slow to drain, incorporate coarse grit before planting, or grow catnip in a raised bed. Water in immediately after planting and keep watered during dry spells for the first couple of months if planting in spring.

How to care for catnip

Catnip is easy to grow and needs very little care once established.

How to propagate catnip

Sow seed from spring to late summer, thinly in a small pot or tray of moist seed compost, and lightly covering the seed. Once seedlings are large enough to handle, transplant into individual 9cm pots and grow on without heat until large enough to plant out.

Divide established clumps that are at least 3 years old, whilst dormant, in autumn or early spring.

How to prune catnip

Once the first main flush of flowers has finished, in late in summer, cut back the stems that have bloomed, leaving the young un-flowered growth. This boosts bushy growth and may encourage a repeated flush of flowers.

In autumn the plant dies back to the ground and the dead stems can be cut back at any time before spring. Leaving the dead growth on as long as possible provides shelter for beneficial insects over winter.

Growing catnip – pests and diseases

Nepeta cataria is generally trouble-free from pests and diseases. Powdery mildew may occur in dry summers and is seen as a white coating on the leaves, but does not require action.