Known as catnip or catmint, Nepeta is a particularly versatile genus that is at home in most habitats, from cool damp spots in the garden to hot, dry rockeries. The genus consists of 250 species and is a member of the Lamiaceae family. It is native to Europe, Asia and Africa. In North America, where it was introduced, it has become a common weed.
Nepeta's chief attraction in a garden setting is its spikes of flowers, which can be white, blue, purple and occasionally yellow. They often last over a long flowering period during the summer. The plant has small, lanceolate leaves and, where it forms clumps, provides an attractive backdrop of grey-blue. Some varieties look very like lavender and can be used as a substitute in areas where lavender is unlikely to thrive. A common use for Nepeta is as an underplanting scheme for roses because it hides the knobbly stems of tall roses while complementing the rose flowers.
The genus is mostly perennial and plants should be cut back after flowering to ensure they keep their compact shape and encourage a second flowering. Taller varieties, such as N. 'Six Hills Giant', which reaches a height of 90cm, can be grown in a mixed herbaceous border and looks particularly good against a background of stone. Tall catnip species also need to be supported to stop them toppling over in the wind and rain.
Smaller varieties, such as N. x faassenii Award of Garden Merit, are good for providing ground cover or can be used as edging plants as they spill attractively over path edges and the edge of raised beds. Many varieties of Nepeta release an aromatic scent when foliage is crushed, which can attract cats as well as other more welcome visitors to the garden such as bees and other insects. Cats can be prevented from flattening the plant if twiggy sticks are inserted into the soil near the plants.
Varieties of this genus can be found for all types of conditions. For example, N. govaniana and N. subsessilis prefer moist, cool soils, while N. sibirica likes fairly dry conditions. N. phyllochlamys can be grown in troughs or dry rock gardens.
Nepeta is extremely easy to care for and does better if left to its own devices. If fertilised it tends to become leggy. Catmint is resilient to most pests and diseases although it can be prone to powdery mildew in dry summers as well as slugs, which like to eat the new growth.
The plant can be grown from seed or propagated by lifting and dividing large clumps in spring. Once established, the plants are usually fairly drought-tolerant, which makes them good for planting in low-maintenance gardens.
WHAT THE SPECIALISTS SAY
Kevin Marsh, grower, Beeches Nursery, Essex - "Traditionally, Nepeta is sold for edging in cottage gardens, though there's lots of other tall varieties people generally don't use, such as N. yunnanensis. It grows to 1.5m and runs, but it has tubular, blue flowers and should be better known. N. sibirica also grows to 1.2m-1.5m while N. govaniana is a pale yellow and grows in moist shade.
"People always associated Nepeta with straightforward cottagey borders but it is more than that. The only drawbacks are that it needs cutting back in midsummer because it gets a bit straggly and long. But there are no real pests and diseases.
"Best-sellers are N. x faassenii Award of Garden Merit (AGM) - the common variety - and N. 'Six Hills Giant', which is like N. x faassenii AGM in a taller form. Then there's the dusky-pink N. grandiflora 'Dawn to Dusk', which is also good."
Linda Lawlor, owner, Bodmin Plant & Herb Nursery, Cornwall - "We're a herb nursery so I do sell a true catmint. Customers do request it to be part of our range. We specialise in herbaceous perennials of a decorative type for country cottage gardens. We sell some tall and some smaller types and they sell well because they're such a gorgeous, varied, typical cottage-garden type of flower.
"N. 'Six Hills Giant' is best for people who want a taller 90cm Nepeta. It's a lavender-blue classic variety people want to plant. I like N. racemosa 'Little Titch', a dwarf grey/green aromatic, compact variety that grows to 15cm. There are no real disadvantages to growing Nepeta. The plant likes a well-drained, sunny site but is not difficult to grow, which is part of its appeal."
David Howard, owner, Howard Nurseries, Norfolk - "N. racemosa 'Walker's Low' is very popular - very good for edging the borders. N. 'Six Hills Giant' is a very strong, tall, old variety. 'Walker's Low' is very similar to 'Six Hills Giant' but has bigger, longer spikes. My advice would be to cut them back that after flowering to get a second crop.
"Nepeta has always been a very popular plant but it is becoming more so because of its long flowering season. It has two flushes and is ideal for edging. The only problem with it is that cats may be tempted to roll in it - hence the name catmint - but that has never been a big issue, really."
Chris Day, plant merchandising manager, Buckingham Nurseries & Garden Centre, Buckinghamshire - "Nepeta is available as a herbaceous plant or as a bedding variety. As far as we're concerned this plant is a must-have for hanging baskets. And its popularity on the herbaceous side is increasing as more people plant roses because Nepeta is a natural complement to rose beds and edging.
"I've not seen massive increases in sales of Nepeta as an edging plant but in the herbaceous border it is very popular because it's drought tolerant. Best varieties are N. glechoma 'Variegata', which is the standard for hanging baskets. The new kid on the block is N. grandiflora 'Dawn To Dusk', while N. 'Six Hills Giant' is the standard tall variety. Then there's N. subsessilis 'Sweet Dreams' as well, which is also popular."
SPECIES AND CULTIVARS
- N. x faassenii Award of Garden Merit (AGM) is a dwarf catmint that produces lavender-blue flowers between June and September. It reaches heights of 45cm with a similar spread.
- N. glechoma 'Variegata' is a trailing variety with cream and green variegated leaves. It is ideal for hanging baskets and containers.
- N. govaniana grows in clumps and produces pale-yellow flowers from mid-summer to early autumn. It grows to a height of 90cm and a spread of 60cm.
- N. grandiflora 'Bramdean' displays spikes of deep lavender-blue flowers on blue stems. It grows to a height of 60cm.
- N. grandiflora 'Dawn to Dusk' has soft pink flowers with soft, hairy, sage-green leaves. It flowers from June to September and grows to a height of 75cm.
- N. nervosa 'Blue Moon' produces large, dense blue flower spikes throughout the summer. It is ideal for borders and containers and reaches a height of 40cm.
- N. racemosa 'Little Titch' has pale lavender-blue flowers and is a dwarf variety growing to a height of 15cm.
- N. racemosa 'Snowflake' has whorls of white flowers and grows up to 30cm.
- N. racemosa 'Walker's Low' produces deep violet to lilac-blue flowers in the summer. If cut back after first flowering, it will continue flowering until the autumn. It likes full sun or partial shade and a moist, well-drained soil. Reaches a height and spread of 50cm.
- N. sibirica 'Souvenir d'Andre Chaudron' will tolerate most soil types and displays large blue flowers in the summer. It forms clumps to a height and spread of 50cm.
- N. 'Six Hills Giant' produces blue flowers on upright stems from June to July. It is fast-growing and will form a dense mound of up to 90cm in height and 60cm wide.
- N. subsessilis 'Sweet Dreams' produces cylindrical pink flowers and grows to a height of 60cm. It prefers moist conditions and has dark burgundy flower bracts.
- N. subsessilis 'Washfield' has spikes of vivid-blue tubular flowers that are held in clusters on erect stems - a magnet for bees and butterflies. It will tolerate heavier clay soils and reaches a height of 70cm.
- N. yunnanensis produces large lavender-purple flowers that are spotted on the lip. It is a tall variety and grows to a height of 1.5m.