Herb · Lamiaceae
Catmint
Nepeta × faassenii
Give it full sun and lean, dry soil, and catmint hums with bees and lavender-blue bloom all summer.
Full sun
Every 7–14 days
USDA 3–8
12–24 in · 30–60 cm
Overview
Catmint is a tough, easygoing perennial in the mint family, grown for the haze of lavender-blue flowers it carries above soft gray-green leaves. It belongs to the genus Nepeta, the same group as true catnip, and most garden catmint is the hybrid Nepeta x faassenii. Once it has its roots down, it asks for almost nothing.
The plant forms a low, spreading mound that bees and other pollinators work all day long. It shrugs off heat, drought, and poor soil, and deer and rabbits tend to leave it alone. Cats are another story, since the nepetalactone in the leaves draws them in to roll and bask, though the pull is gentler than true catnip.
What it wants most is sun and sharp drainage. Plant it in lean ground, hold back on water once it's established, and shear it after the first bloom, and it will flower from late spring deep into summer. Pamper it with rich soil and heavy feeding instead, and you get floppy, open growth that splits down the middle.
Care
The short version: full sun and lean, well-drained soil, water deeply but only now and then once it's established, skip the heavy feeding, and shear it back after the first flush of bloom to keep it tidy and flowering.
Light
Catmint flowers hardest in full sun, where the growth stays dense and upright. It will take some light shade, but too little sun gives you weak, floppy stems and far fewer blooms.
Water
Water deeply but not often, roughly every 7 to 14 days, and let the top half of the soil dry out in between. Once established the plant is genuinely drought-tolerant, and soggy ground is the fastest way to rot its roots.
Soil
Plant it in lean, well-drained soil rather than anything rich. It handles dry to medium moisture and a wide range of textures, and a pH from 6.0 to 7.5 suits it fine. Sharp drainage matters more than fertility.
Temperature
This is a remarkably hardy plant, taking everything from -40°F to 95°F (-40°C to 35°C). It rides out hard winters and shrugs off summer heat without complaint.
Humidity
Catmint likes things dry, around 30% to 50% humidity, and resents muggy, stagnant air. Good airflow keeps powdery mildew off the leaves.
Feeding
Go light. One feeding in spring with a balanced fertilizer or a little compost is all it needs for the whole year. Rich soil or extra feeding just grows soft, floppy stems.
Pruning
Shearing is the key to a good-looking plant. Cut it back by a third to a half after the first flush of bloom to keep it compact and bring on a second round of flowers, then cut the whole thing to the ground in late winter.
Repotting
Catmint lives in the ground, not a pot. Every 3 to 4 years, dig and divide the clump to refresh it, especially once the center goes bare or the flowering tails off.
Size & spacing
Plants grow 12 to 24 inches (30 to 60 cm) tall and spread 18 to 35 inches (45 to 90 cm) wide. Give each one room to fill out so air moves freely and mildew stays away.
When to plant
Catmint runs on a simple seasonal rhythm. Set plants out in spring once the frost has passed, enjoy the lavender-blue spikes from late spring through summer, and shear after the first flush to coax a second wave 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 rarely gives much trouble, and most of what does go wrong traces back to too much water or too rich a site. Watch the stems and leaves, and you can usually fix things with a hard shearing or better drainage. Match what you see below, then act early.
Wilting and sudden collapse in wet ground
Root rot from Pythium or Phytophthora sets in when the soil stays soggy, and by the time the plant wilts the roots have already turned black and mushy. There is no saving a badly affected plant. Pull it, fix the drainage, and replant somewhere dry, cutting back hard on the water.
Fix:
- Improve drainage and remove affected plants
- Replant in well-drained soil and reduce watering
The plant flops open and splits down the middle after flowering
This is flopping, and it sets in once the first flush of bloom fades and the stems grow heavy. Rich soil and too little sun only make it worse, leaving the growth soft and weak. Shear the plant back by a third to a half, and keep it in full sun and lean ground so the mound holds its shape.
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 white powdery film coating the leaves
This is powdery mildew, a fungus that takes hold when the air is humid and the plant sits crowded with little airflow. Open things up by spacing or dividing the clumps, shear off the worst of the coated growth, and water at the base rather than over the top.
Fix:
- Improve air circulation by spacing or dividing plants
- Shear affected growth and avoid overhead watering
Bloom slows or stops after the first flush
When the spent flower spikes are left standing, the plant pours its energy into seed instead of fresh buds. Shear the old spikes off after that first flush and grow the plant in full sun, and a second wave of bloom usually follows.
Fix:
- Shear flower spikes after initial flowering to promote continued bloom
Foliage flattened and matted where cats have rolled
The nepetalactone in the leaves draws cats in, and they roll on the plant and crush the stems flat. The plant bounces back, but young ones can be loved to death. Cage new plantings until they root in, or set them where cats roam less.
Fix:
- Protect young plants with a low cage or grow where cats have less access
Toxicity
Good news for pet owners: catmint is safe across the board. The ASPCA lists Nepeta as non-toxic to cats and dogs, and there's no risk to horses, rabbits, livestock, birds, or people. Cats are simply drawn to the nepetalactone in the leaves, which leaves them happily rolling and rubbing with no harm done.
Safe for
People · Cats · Dogs · Horses · Rabbits · Livestock · Birds
Cats Safe
Catmint is safe, and most cats are drawn straight to it. The nepetalactone in the leaves leaves them rolling, rubbing, and blissed out, a harmless buzz that wears off on its own. A cat that gorges on it might be briefly sick, but that passes quickly.
Dogs Safe
Safe for dogs, who mostly ignore it since the scent does nothing for them. A curious dog can nibble the foliage with no harm done.
Horses Safe
No risk to horses. They can graze near a planting without any concern.
Rabbits Safe
Rabbits can browse the leaves safely, though the strong minty scent often keeps them away in the first place.
Livestock Safe
Cattle, goats, and sheep come to no harm from it, and the aromatic foliage rarely tempts them anyway.
Birds Safe
Harmless to birds. The plant earns its keep instead by pulling in the bees and other pollinators that visit its flowers.
People Safe
Safe for people too. The leaves have a long history in herbal teas, and handling or brushing past the plant poses 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 garden catmint comes from a short list of named hybrids, each with its own size and habit. These are the ones worth knowing by name.
'Walker's Low'
Named Perennial Plant of the Year in 2007, it forms a large mound despite the name and ranks among the most popular long-blooming catmints.
'Six Hills Giant'
A vigorous, taller cultivar that reaches up to about 3 feet and throws out masses of lavender-blue spikes.
'Purrsian Blue'
A compact, tidy mound with deep periwinkle-blue flowers set off by reddish calyxes.
How to propagate
Catmint is easy to multiply, but because the common garden hybrid is sterile, you split it or take cuttings rather than save seed.
DivisionEasy
Spring or early fall · About one growing season
Division is the go-to method for these sterile named hybrids. Lift an established clump in spring or early fall, split it apart, and replant, and the divisions settle in over about one growing season.
Stem cuttingsModerate
Late spring to summer, from non-flowering shoots · A few weeks to root
Cuttings are the other reliable route for sterile hybrids. Take softwood from non-flowering shoots in late spring or summer, and they strike roots in a few weeks.
SeedModerate
Late winter to spring · Several weeks to germinate
Seed only works for true species or seed-grown types, not this plant. Nepeta x faassenii is a sterile hybrid of N. racemosa and N. nepetella, so it rarely sets viable seed and must be divided or grown from cuttings instead. Where seed does apply, sow from late winter into spring and expect germination over several weeks.
Myths
Catmint and catnip are the same plant and hit cats just as hard.
Catmint is the ornamental cousin of true catnip, the garden plant Nepeta cataria. It carries the same nepetalactone, so cats still respond, but the effect is usually milder.
Catmint is toxic or poisonous to pets.
The ASPCA lists Nepeta as non-toxic to both cats and dogs. It is not a poison, and a cat rolling in it or nibbling a leaf is in no danger.