Catmint: complete guide

Overview

Catmint (Nepeta faassenii) is the unsung hero of the summer border. While roses, lavender, and ornamental grasses steal the spotlight, catmint is the tireless performer that blooms from May well into September in soft blue-violet haze. This herbaceous perennial from the mint family combines aromatic grey-green foliage with swaying flower spikes that draw bees, butterflies, and hoverflies in remarkable numbers. It is the plant you can depend on: drought-proof, disease-free, fully hardy, and virtually maintenance-free.

The common name refers to the effect the plant has on some cats — the aromatic foliage contains nepetalactone, a compound related to that in true catnip (Nepeta cataria), though the reaction to N. faassenii is usually milder. On gardenworld.app you can create a garden design featuring catmint as a border edging, as a rose companion, or massed for a naturalistic drift. With cultivars ranging from compact (30 cm) to substantial (80 cm), there is a catmint for every garden situation from a London courtyard to a rural cottage garden in the Cotswolds.

Appearance and bloom

Nepeta faassenii forms compact, semi-spherical mounds 30 to 50 centimetres tall, depending on the cultivar. The leaves are small, oval to heart-shaped, grey-green and finely hairy, giving the plant a silvery sheen. When brushed, the foliage releases a pleasant minty-herbal scent that most people find refreshing.

The flowers appear from May onwards in slender, upright spikes that rise above the foliage. The colour is a characteristic blue-violet ranging from lavender-blue to deep purple, depending on cultivar and soil chemistry. The bloom is exceptionally long-lasting: the first flush runs from May to July. If you shear the plant back at that point (more on this in the pruning section), a second flush follows from August into September or even October.

Popular cultivars include 'Walker's Low' (50–60 cm, the most widely planted selection, Perennial Plant of the Year 2007), 'Six Hills Giant' (60–80 cm, the largest form, impressive as a specimen group), and 'Junior Walker' (30–40 cm, compact, ideal for small gardens and containers). Lesser-known but valuable selections include 'Purrsian Blue' (very compact, 35 cm) and 'Cat's Pajamas' (40 cm, deep blue).

Ideal location

Catmint is a thoroughbred sun lover. Give it a spot in full sun — at least six hours of direct sunlight per day — and it rewards you with abundant, sustained bloom. In partial shade the plant flowers noticeably less and the foliage turns greener and less silvery. In shade, catmint performs poorly: the plant becomes lank, barely flowers, and is more susceptible to fungal diseases.

Its drought tolerance and love of warmth make catmint perfectly suited to hot, dry garden situations: along a south-facing wall, in a gravel garden, on a slope, or in a raised bed that dries out quickly. The plant handles heat, wind, and even the microclimate of a city garden without complaint. In coastal gardens from Brighton to Cape Town, catmint thrives in the salt-laden breeze where many other perennials would struggle.

Soil requirements

The golden rule for catmint: well-drained soil. The plant detests wet feet and inevitably declines on heavy, poorly drained clay where water sits through winter. On light, free-draining ground — sand, loam, or chalky soil — catmint flourishes. A somewhat lean soil actually produces better results than very rich ground: on overly fertile soil the plant becomes floppy and loses its compact shape.

If your garden sits on heavy clay, improve drainage by working generous handfuls of coarse grit or gravel into the planting hole. On a raised bed or in a gravel garden you have the right conditions immediately. Catmint also performs beautifully in pots and troughs, provided the growing medium drains freely — a mix of multi-purpose compost and perlite at roughly 70/30 works well. Garden centres across the UK, USA, and Australia stock catmint reliably from spring through summer.

Watering

Catmint is one of the most drought-tolerant perennials available. Once established — after the first growing season — the plant needs virtually no supplementary water. Its extensive, finely branched root system draws moisture from deeper soil layers, and the hairy foliage limits evaporation.

Only during the establishment year does catmint require regular watering: give a thorough soaking once a week in dry weather until the roots have settled. After that, watering is only necessary during extreme heat or prolonged drought — and even then, a single thorough soaking every two weeks is sufficient. Always water the root zone and avoid wetting the foliage, as prolonged leaf moisture can encourage powdery mildew.

Overwatering is more damaging than underwatering. A catmint that is too wet becomes floppy, develops yellow leaves, and can suffer root rot. Keep this in mind when designing your border: do not plant catmint next to moisture-loving plants with different irrigation needs.

Pruning

Pruning is the secret to a long and lavishly blooming catmint. After the first flowering flush (late June to early July), shear the entire plant back to roughly one-third of its height. Use large hedge shears or hand shears and cut everything in one go — flowers, stems, and some foliage. It looks drastic, but the plant recovers with remarkable speed.

Within two to three weeks, fresh grey-green foliage appears, and shortly after, the second flowering flush begins, lasting well into autumn. This 'Chelsea chop' — named after the Chelsea Flower Show, around which the cut traditionally takes place — is the single most important maintenance task for catmint.

In early spring (March), remove the old, dead foliage and cut the plant back to just above ground level, where you can see the new growth emerging. Remove the dead material completely, as it otherwise harbours slugs and fungal spores.

Maintenance calendar

March: Cut away the old, dead stems to just above the new growth. Apply a light feed with a balanced organic fertiliser or a handful of compost.

April–May: The plant grows rapidly and begins to flower. No specific action needed beyond enjoyment.

June–July: After the first flush: shear the plant back to one-third of its height. This is the most important pruning of the year. Give a light feed after cutting back to fuel regrowth.

August–September: The second flush appears. Enjoy the blue-violet colour display. Water only during extreme drought.

October–November: Flowering tapers off. Leave the dead stems standing as winter insulation and shelter for beneficial insects.

December–February: Dormancy. The plant has died back completely above ground. Do not prune; wait until March.

Winter hardiness

Nepeta faassenii is outstandingly hardy to -30°C and below (USDA zones 3–8). In the UK, most of the USA, and the temperate regions of Australia and South Africa, winter cold is never an issue. The plant dies back above ground in autumn and overwinters as a rootstock protected by the soil. The dead foliage and stems provide additional insulation — leave them in place until spring.

The only winter risk is not cold but wet soil. On poorly drained ground the rootstock can rot away during a wet winter. Ensure good drainage — this is the single most important measure for the long-term survival of your catmint. Container plants are slightly more vulnerable: move the pot against a sheltered wall in severe frost or wrap it in bubble wrap.

Companion plants

Catmint is renowned as the ultimate rose companion, and the reputation is thoroughly deserved. The soft blue-violet flowers form a dreamy contrast with pink, white, and red roses, while the grey-green foliage neatly conceals the bare lower stems of the rose bush. Classic pairings include catmint at the feet of Rosa 'New Dawn', 'The Fairy', or 'Bonica'. You will find this combination in great English gardens from Sissinghurst to Mottisfont — and it works just as well in a suburban border in Portland, Oregon, or a courtyard in Melbourne.

Beyond roses, catmint pairs beautifully with other sun-loving, drought-tolerant plants: lavender (Lavandula angustifolia), ornamental sage (Salvia nemorosa), yarrow (Achillea), ornamental grasses such as Stipa tenuissima, and alliums (Allium). In a modern naturalistic border, a large drift of catmint with grasses and Verbena bonariensis creates a breathtaking picture.

Avoid combining catmint with shade plants or moisture-loving plants — the mismatch in growing requirements will inevitably cause problems for one or both.

Closing

Catmint is one of those rare perennials that does almost everything right: months of bloom, minimal water needs, freedom from disease, and a tidy appearance all season. It is the reliable backbone of any sunny border, the ideal partner for roses, and the saviour of every hot, dry garden corner.

Buy your plants from a good garden centre or order from a specialist perennial nursery — choose a named cultivar such as 'Walker's Low' or 'Six Hills Giant' for the best results. On gardenworld.app you can create a garden design where catmint plays the starring role, as a border edge, a rose companion, or a naturalistic mass. Plant a group of catmint this spring and discover how this modest perennial fills your garden with colour and life for months on end.