Herb · Lamiaceae
Catmint
Nepeta × faassenii
Set it in full sun and lean, dry soil, and catmint clouds itself in lavender-blue spikes alive with bees all summer.
Full sun
Every 7–14 days
USDA 3–8
12–24 in · 30–60 cm
Overview
Catmint is a hardy, undemanding perennial in the mint family, grown for the soft haze of lavender-blue flower spikes that floats above its gray-green leaves. It sits in the genus Nepeta alongside true catnip, and most garden plants are the hybrid Nepeta x faassenii. Once its roots take hold, it asks for next to nothing.
It settles into a low, spreading mound of minty foliage that bees and other pollinators comb over from dawn to dusk. Heat, drought, and thin soil barely register, and deer and rabbits mostly pass it by. Cats are the exception, since the nepetalactone in the leaves lures them in to roll and lounge, though the pull runs softer than true catnip.
Above all it craves sun and quick-draining ground. Set it in lean soil, ease off the water once it is settled, and shear it back after the first bloom, and it spikes lavender-blue from late spring well into summer. Feed it heavily on rich earth instead, and the stems turn soft and floppy and split open at the heart of the mound.
Care
The short version: full sun and lean, well-drained soil, a deep soak only now and then once it has settled in, almost no feeding, and a hard shear after the first flush of bloom to keep the mound neat and flowering.
Light
Catmint blooms heaviest in full sun, where the foliage stays thick and the stems hold upright. A touch of light shade is fine, but in too little sun the stems go weak and floppy and the spikes thin right out.
Water
Soak it deeply but not often, somewhere around every 7 to 14 days, letting the top half of the soil go dry in between. Settled in, the plant is truly drought-tolerant, and wet ground is the surest way to rot the roots.
Soil
Give it lean, well-drained soil in place of anything rich. It copes with dry to medium moisture and many soil textures, and a pH from 6.0 to 7.5 sits well with it. Sharp drainage counts for far more than fertility.
Temperature
This plant is tough through and through, riding out everything from -40°F to 95°F (-40°C to 35°C). It weathers brutal winters and shrugs off blistering summers without a complaint.
Humidity
Catmint prefers things dry, in the range of 30% to 50% humidity, and bristles at heavy, stagnant air. A steady breeze keeps powdery mildew off the gray-green leaves.
Feeding
Keep it light. A single feeding in spring with a balanced fertilizer or a scoop of compost carries it through the year. Rich ground or extra feeding only grows soft, floppy stems.
Pruning
Shearing is what makes the difference. Take it back by a third to a half after the first flush to hold the mound compact and trigger a second run of flowers, then cut the whole plant to the ground in late winter.
Repotting
Catmint belongs in the ground, never a pot. Every 3 to 4 years, lift and split the clump to renew it, above all once the center hollows out or the flowering starts to fade.
Size & spacing
Each plant rises 12 to 24 inches (30 to 60 cm) tall and spreads 18 to 35 inches (45 to 90 cm) across. Leave room for the mound to fill in so air moves freely and mildew has no chance to settle.
When to plant
Catmint keeps to a plain seasonal beat. Set the plants out in spring once frost has cleared, watch the lavender-blue spikes climb from late spring through summer, and shear hard after the first flush to draw out a second round of bloom.
Northern hemisphere
Southern hemisphere
Typical months for a temperate climate: start earlier in warm zones, later where spring frosts linger.
- Plant: Spring, after danger of frost has passed
- Harvest: Lavender-blue flower spikes from late spring through summer (roughly May to September); shear after the first flush to encourage a second bloom
Hardiness
USDA hardiness zones: 3–8
Temperature: down to -40°C
Troubleshooting
Catmint asks for little and seldom falters, and what does go wrong almost always comes back to too much water or too rich a spot. Keep an eye on the stems and leaves, and a hard shearing or better drainage usually puts it right. Find what matches below, then move on it early.
Sudden wilting and collapse where the ground stays wet
Root rot driven by Pythium or Phytophthora takes hold in soil that never dries, and the roots turn black and slimy underground before the top ever droops. A plant this far gone cannot be saved. Lift it out, correct the drainage, and set a fresh one in dry ground while easing well off the water.
Fix:
- Improve drainage and remove affected plants
- Replant in well-drained soil and reduce watering
The mound pulls apart at its core once the flowers fade
This is flopping. As the first wave of bloom dies back, the spent stems grow top-heavy and lean outward, dragging the soft gray-green mound open at its middle. Rich ground and shade make the stems weaker still. Cut the plant back by a third to a half, and grow it in full sun on lean soil so the low mound stays knit together.
Fix:
- Shear the plant back by one-third to one-half after first flowering
- Grow in full sun and lean soil to keep growth compact
A dusty white film settles over the gray-green leaves
This is powdery mildew, a fungus that creeps across the foliage when air sits damp and still around a crowded plant. Loosen the planting by spacing or dividing the clumps, clip away the worst of the chalky-coated growth, and aim water at the roots instead of wetting the leaves overhead.
Fix:
- Improve air circulation by spacing or dividing plants
- Shear affected growth and avoid overhead watering
The spikes thin out once the first flush is spent
Left standing, the faded flower spikes pull the plant's energy toward setting seed rather than pushing new buds. Shear those tired spikes off the moment the first flush ends and keep the plant in full sun, and a fresh run of lavender-blue spikes usually rises behind it.
Fix:
- Shear flower spikes after initial flowering to promote continued bloom
Stems pressed flat and tangled where cats have lain
The nepetalactone held in the minty leaves pulls cats straight to the plant, and they roll on it until the stems lie crushed and matted. Mature clumps spring back, but a young plant can be flattened to death. Cage fresh plantings until the roots take, or tuck them where cats wander less.
Fix:
- Protect young plants with a low cage or grow where cats have less access
Toxicity
Pet owners can relax: catmint is safe right down the line. The ASPCA marks Nepeta as non-toxic to cats and dogs, with nothing to fear for horses, rabbits, livestock, birds, or people. Cats simply chase the nepetalactone in the leaves, which leaves them rolling and rubbing in happy contentment and none the worse for it.
Safe for
People · Cats · Dogs · Horses · Rabbits · Livestock · Birds
Cats Safe
Catmint is safe, and most cats make a beeline for it. The nepetalactone in the leaves sets them rolling, rubbing, and drifting off into a harmless daze that fades on its own. A cat that overdoes it may feel briefly off, but the upset clears fast.
Dogs Safe
Safe for dogs, who tend to walk right past it because the scent means nothing to them. Should a curious one chew a leaf, no harm comes of it.
Horses Safe
No risk to horses. They can graze beside a stand of it with nothing to worry about.
Rabbits Safe
Rabbits can nibble the leaves with no harm, though the sharp minty smell usually steers them off before they try.
Livestock Safe
Cattle, goats, and sheep take no harm from it, and the aromatic foliage rarely draws them in to begin with.
Birds Safe
Harmless to birds. Its real value comes from the bees and other pollinators that crowd the flowers all day.
People Safe
Safe for people as well. The leaves have long flavored herbal teas, and brushing past or handling the plant carries no risk.
Non-toxic. Contains nepetalactone and may mildly attract and excite cats (a harmless behavioral effect, generally weaker than true catnip, Nepeta cataria). Large ingestion may occasionally cause mild, self-limiting vomiting or diarrhea, but it is not a poison.
Varieties
Most catmint in gardens traces back to a handful of named hybrids, each cut to its own size and shape. These are the few worth recognizing on sight.
'Walker's Low'
Crowned Perennial Plant of the Year in 2007, this one builds a broad mound in spite of the name and stands among the most popular long-blooming catmints.
'Six Hills Giant'
A strong, taller grower that climbs to about 3 feet and sends up dense masses of lavender-blue spikes.
'Purrsian Blue'
A neat, compact mound carrying deep periwinkle-blue flowers framed by reddish calyxes.
How to propagate
Catmint multiplies easily, but since the common garden hybrid is sterile, you divide it or take cuttings rather than gather seed.
DivisionEasy
Spring or early fall · About one growing season
For these sterile named hybrids, splitting the clump is the usual route. Dig an established plant in spring or early fall, pull it apart into pieces, and set them back in, and the divisions root down over roughly one growing season.
Stem cuttingsModerate
Late spring to summer, from non-flowering shoots · A few weeks to root
Cuttings work just as well for the sterile hybrids. Snip softwood from shoots that are not flowering in late spring or summer, and the pieces send out roots within a few weeks.
SeedModerate
Late winter to spring · Several weeks to germinate
Seed suits only true species or seed-grown forms, not this one. Nepeta x faassenii is a sterile cross of N. racemosa and N. nepetella, so it seldom sets viable seed and has to be divided or struck from cuttings. Where seed does fit, sow from late winter on into spring and look for germination across several weeks.
Myths
Catmint is just another name for catnip and drives cats every bit as wild.
Catmint is the ornamental relative of true catnip, the herb Nepeta cataria. It holds the same nepetalactone, so cats still react, but the pull is usually gentler.
Catmint will poison a pet that gets into it.
The ASPCA records Nepeta as non-toxic to both cats and dogs. It is no poison, and a cat rolling through it or chewing a leaf comes to no harm.