What is catnip and how to grow it

What is catnip?  

Name: Catnip (Nepeta cataria).

Height: 30-100cm x 80cm.

Plant type: Perennial.

Climate: Sub-tropical, warm temperate, sheltered areas in cool temperate.

Soil: Prefers quality, free-draining soil but adaptable.

Position: Full-sun with protection from afternoon sun in hotter regions. 

Flowering: Spring through to early autumn, depending on climate zone.

Feeding: Improve soil with quality compost or manures at planting time. Applications of controlled-release fertiliser.

Watering: Water during hot, dry periods. Avoid over-watering.

Appearance and characteristics

With the name cataria literally translating to ‘of cats’ it’s little surprise that catnip has long been recognised for its effect on felines. So, exactly what does catnip do to cats? An aromatic component of the plant’s natural oils, nepetalactones, brings on a range of responses, anything from playfulness to euphoria. Interestingly around one-third of cats don’t react to it at all.

Catnip is in the plant family Lamiaceae, a very broad group of nearly 200 different species many of which, like catnip, are very aromatic. Catnip’s cousins include well-known herbs such as basil, mint, lavender, sage and rosemary.

Catnip is considered as being from the Eurasian regions and has also naturalised in many areas globally. A small to medium sized perennial shrub-like plant, the size varies depending on plant health and vigour so may be anything from 30cm to 1m high.

Generally, the plants are multi-stemmed and form a loose, open mound. Leaves are light green with a grey to white hue due to them being covered, especially on the underside, with fine hairs. Leaf shape is extremely variable, anything from oval to arrow to cordate (heart) shaped, however they always have wavy, toothed margins and they are up to 7cm in length.

Flowers are born at the end of branches on loosely arranged spikes of anywhere from 2-8cm in length. In ideal conditions catnip blooms from spring until autumn. This can be encouraged by removing flower spikes as they finish. The flowers on the spikes are quite tiny and have a reasonably strong perfume. Look closely and you’ll see that each flower is off-white to pink and they are often dotted with spots in purples and pinks.

Uses for catnip

Most often grown by cat lovers as a treat for their fur buddies, catnip can also be a very useful ornamental perennial for a cottage-style garden and grows well in pots, too. Catnip is used around the vegetable garden, as it attracts pollinators such as bees and butterflies, and is said to attract lacewings, which eat aphids and other smaller pests, while also working to repel some garden insect pests. Catnip has a long history of use in traditional medicine too.

How to plant and grow catnip

The ideal conditions are full sun in free-draining soil with reliable moisture. However, catnip is very adaptable and will tolerate a little shade, with protection from afternoon sun preferred in the hottest spots. It can grow in virtually any soil, except those that are prone to water-logging, and is considered as drought tolerant once established. If clay is present, then raised planting mounds or raised beds will give better results.

Planting tips

• Improve soil with a quality compost or composted manure at planting time.
• Apply a controlled-release fertiliser for flowering plants at the recommended intervals.
• Mulch well with lucerne to help retain moisture and enhance establishment and new leaf growth.

Caring for catnip

Remove any dead or dying shoots and trim flower spikes as they finish to bring on another flush of blooms. After the flowering period has ended, give the entire plant a light haircut. If plants die-back during winter, tidy up the stems as they finish. Leaving them on for as long as possible allows the plant to store energy for next season.

Watering catnip

• Water well at planting; using a seaweed tonic will be beneficial.
• Keep reliably moist until well established.
• Once established, watering will likely only be required during very hot or extended dry periods.
• When planted in pots avoid using a saucer and water frequently. Catnip tolerates drying out a little but not completely.

How to propagate catnip

• Allow some flower spikes to go to seed, harvest and sow in a moist seed-raising mix in autumn.
• Older, well-established plants can be lifted and divided in spring or autumn.
• Early in the growing season softwood cuttings can be taken and will strike well in a propagating mix. Using a rooting hormone product will increase the strike rate.

Diseases and pests

Catnip may be afflicted with rot in conditions where the roots stay too wet. And they may suffer with fungal conditions, such as powdery mildew on the leaves, in extended, very humid conditions.

Keep in mind...

• Wear gloves and a mask when handling mulch, compost and potting mix and also when pruning, along with long sleeves, as the leaves and sap of some plants can be a skin irritant and cause allergic reactions.
• Store garden chemicals and products out of reach of children and pets.

Looking for a bit of guidance in the garden?

Check out our series of location-specific articles to help you green up your thumb.

Photo credit: Adobe Stock