Herb · Asteraceae
Roman Chamomile
Chamaemelum nobile
Give it full sun and dry feet and it spreads into a soft apple-scented mat of feathery green.
Full sun
Every 7–10 days
60–90 days
USDA 4–9
Overview
Roman chamomile is a low, mat-forming perennial in the daisy family that hugs the ground and creeps outward rather than standing tall. Its foliage is finely divided and feathery, soft to the touch, and the leaves release a warm, apple-like scent the instant you brush or crush them. Gardeners grow it as much for that smell as for its bloom, working it into fragrant lawns and along the edges of paths where feet keep waking the fragrance.
Through summer the mat lifts small white-and-yellow daisy flowers on short stems, a ring of clean white petals around a low yellow eye. You harvest the flower heads when the petals lie flat or have just opened fully, then dry them for tea. The more sun the planting catches, the denser the green mat and the heavier that flush of bloom.
Up close the plant reads as a fine-textured green cushion, 6 to 12 inches (15 to 30 cm) tall and spreading 12 to 18 inches (30 to 45 cm) wide as it mats outward. It is rated easy to grow and hardy across zones 4 to 9, holding through cold down to zone 4. Give it light and drainage and it largely runs itself.
Care
The short version: picture a low green carpet of finely cut, feathery leaves that throws off a warm, apple-like smell the moment your hand grazes it. Roman chamomile wants strong light and gritty, fast-draining ground, and it asks for very little once its roots take hold. Let the top half of the soil go dry before you water, keep it lean on food, and shear the mat after the small white-and-yellow daisies finish. Sharp drainage and moving air are what keep it dense and green; soggy ground and dead, muggy air are what turn it black or brown.
Light
Set this chamomile where the sun pours over it. Full sun is what it wants, and the difference shows in the plant itself, a tighter, denser green mat and far more of the little daisies. It will hold in partial shade, but the foliage thins and the bloom drops off. More light, more flowers and a fuller carpet.
Water
Water with a light hand and let the soil do most of the talking. Allow the top half of the soil to dry between drinks, which usually lands around every 7 to 10 days, then water moderately. Once its roots are settled the plant turns drought-tolerant and shrugs off dry spells. Standing wet ground is the danger, since soggy soil rots the roots and is the quickest way to lose the whole mat.
Soil
Plant it in something light and quick to drain, a sandy loam that water runs straight through. It is happy across pH 5.6 to 7.5, but the texture matters far more than the number; sharp drainage is what keeps the roots alive. If your ground is heavy clay, cut grit into it to open it up before the feathery crowns go in.
Temperature
This is a cool-to-warm grower, comfortable through 39°F to 86°F (4°C to 30°C) and tough down through zone 4, with an overall range of zones 4 to 9. The hard season is summer; drawn-out heat and humidity punish the center of the mat, leaving it thin and brown in the middle while the cooler edges keep their green.
Humidity
Keep it on the dry side, somewhere around 30% to 50%, and pay more mind to the air moving over it than to the moisture in it. Still, muggy air settling into the foliage invites fungal dieback that browns out the leaves. Open spacing and a breeze across the mat count for more here than humidity itself.
Feeding
Feed it almost nothing. This is a light feeder, content with little to no fertilizer, and a single balanced, low-nitrogen feed in spring covers the whole year. Push more food at it and you get soft, lush growth, exactly the tender shoots that aphids swarm, so keep the diet lean.
Pruning
After the daisies fade, run a light shear or mow across the top of the mat. That trim keeps the carpet thick and tight and pushes a wave of fresh green growth from the base. Deadheading spent flowers along the way keeps new buds coming and stretches the bloom further into the season.
Repotting
In the ground it rarely needs disturbing. In a container, divide and refresh every 2 to 3 years, or step in sooner if you see the roots circling the pot, the growth thinning out at the crown, or the soil drying far too fast after a watering. A split and fresh, gritty mix sends it off again.
Size & spacing
Expect a fine green mat 6 to 12 inches (15 to 30 cm) tall that spreads 12 to 18 inches (30 to 45 cm) wide as the plants knit together. Set them close if you want a continuous chamomile lawn, or leave gaps between them so they grow into separate, tidy cushions of feathery foliage.
When to plant
The rhythm of this plant tracks the seasons through its foliage and flowers. Sow seed indoors in late winter, then set the young, feathery seedlings out in spring once frost has passed and the soil has warmed under them. Through summer the small daisies open in waves, and you pick the flower heads as each one flattens out.
Northern hemisphere
Southern hemisphere
Typical months for a temperate climate: start earlier in warm zones, later where spring frosts linger.
- Sow: Late winter to early spring, 6-8 weeks before the last frost
- Plant: Spring, after the last frost when soil has warmed
- Harvest: White-and-yellow daisy flowers in summer; harvest flower heads when the petals are flat or just fully opened
Hardiness
USDA hardiness zones: 4–9
Temperature: down to -34°C
Troubleshooting
Most trouble shows up first in the look of the plant, in the color of the foliage and the shape of the buds. Sticky, curled leaves and distorted buds point one way; a mat that goes thin, brown, and dead in the middle points another; limp, yellowing stems collapsing in wet ground point to the worst case. Read what the leaves and stems are telling you and match the fix to the sign.
Wilting and yellowing with collapse in wet soil
The stems go limp and yellow and the plant caves in while the ground stays wet. This is root rot out of poorly drained or overwatered soil, and below the surface the roots turn black and mushy. A plant gone that far cannot be saved. Fix the conditions by improving drainage and cutting back on water, and pull and discard any plants that are badly hit.
Fix:
- Improve soil drainage
- Reduce watering frequency
- Remove and discard severely affected plants
Center of the mat thins, browns, and dies out
In hot, humid weather the heart of the mat thins, browns, and dies back while the cooler edges hang on. The trigger is heat and humidity stress, sometimes paired with fungal dieback where the air sits still. Shear the planting back to spark fresh basal growth, thin it to let air move through, and give it afternoon shade in genuinely hot climates.
Fix:
- Shear back to encourage fresh basal growth
- Improve air circulation by thinning
- Provide afternoon shade in hot climates
Distorted sticky buds with clustered insects
The flower buds come up twisted and tacky with small bugs packed onto them and the bloom count drops. The cause is aphids on the buds, often spurred by too much nitrogen pushing soft growth. Confirm it by the soft-bodied insects and the shiny honeydew they leave behind. Blast them off with a strong jet of water, follow with insecticidal soap, and invite ladybugs in. Keep it from returning by easing off fertilizer and opening up the air around the plant.
Fix:
- Spray plants with a strong jet of water
- Apply insecticidal soap to affected buds
- Encourage beneficial predators such as ladybugs
Sticky curled foliage with small insects underneath
The feathery leaves turn sticky and curled with knots of tiny insects gathered on their undersides. That is aphids feeding on tender foliage. Check the leaf undersides for the aphids themselves and the glossy honeydew to be sure. Hose the foliage down hard, treat with insecticidal soap, and back it up by supporting beneficial insects and ladybugs.
Fix:
- Hose off foliage with water
- Apply insecticidal soap
Toxicity
Those small flowers steep into a gentle, soothing tea that most people drink without a second thought, yet the ASPCA still lists the plant itself as mildly toxic to cats, dogs, and horses. Volatile oils and anthemic acid sit in the feathery foliage and can bring on vomiting, an itchy rash, and, with steady long-term chewing, a tendency to bleed. Enjoy the cup, and keep grazing pets clear of the living plant.
Toxic to
Cats · Dogs · Horses · Rabbits · Livestock · Birds
Safe for
People
Cats Mild
The ASPCA flags chamomile as mildly toxic to cats. A cat that nibbles it may drool, vomit, or turn away from food, and the volatile oils can leave an itchy, irritated rash wherever the plant meets skin. The real concern is steady chewing over weeks, since anthemic acid can thin the blood and raise the risk of bleeding.
Dogs Mild
Dogs show much the same mild reaction, an upset stomach, loose stools, and poor appetite after a curious chew. Brushing against crushed foliage can bring on contact dermatitis. Watch a dog that grazes it day after day, because long-term exposure can build toward a bleeding tendency.
Horses Mild
Grazing horses get off comparatively lightly, with mild digestive upset, dull appetite, and the odd skin reaction. A single mouthful poses no acute danger, but the same blood-thinning effect accumulates with chronic grazing, so keep horses away from chamomile borders and pasture stands.
Rabbits Caution
Rabbits are not on the ASPCA's list, but the same volatile oils make this a poor pick for a grazer that small. A single nibbled flower head is unlikely to harm, though steady browsing could bring soft stools or appetite loss, so keep it out of their reach.
Livestock Caution
Cattle, goats, and sheep tend to leave the bitter, aromatic foliage alone, and a few mouthfuls rarely cause trouble. Still, treat it with caution, since the same volatile oils and tannins that bother pets can irritate a grazing animal's gut if it eats a large amount.
Birds Caution
There is little solid data either way for birds. It is not known to be dangerous to them, but the irritant oils mean a pet bird should not graze it freely, and any deliberate herbal use is worth running past an avian vet first.
People Safe as tea
The flowers are the classic base for a calming cup of tea and are safe to drink for most people. The catch is the daisy-family link: anyone allergic to ragweed or related plants can react, and handling the fresh foliage sometimes leaves a mild skin rash.
Handling or crushing the foliage can cause contact dermatitis in sensitive people and animals; wash hands after handling and keep grazing or chewing pets away.
Helpline numbers
United States
ASPCA Animal Poison Control: (888) 426-4435 (fee applies)
United Kingdom
Animal PoisonLine: 01202 509000 (fee applies)
Australia
Animal Poisons Helpline: 1300 869 738
Varieties
A couple of named forms shift what the plant looks like at ground level and in bloom. One trades flowers for a pure, even green carpet; the other rebuilds the simple daisy into something rounder and fuller. Pick by the texture and flower form you want underfoot.
'Treneague'
'Treneague' is a non-flowering, low-growing form prized for fragrant chamomile lawns, and because it sets no seed it only spreads when you divide the mat.
'Flore Pleno'
'Flore Pleno' is a double-flowered form whose blooms are rounded and fuller in creamy white, standing in for the simple single daisy.
How to propagate
You can start more of this chamomile from seed or by splitting a mat that has already knit together. The dust-fine seed sits right on the surface and greens up into feathery seedlings, while a lifted clump arrives already rooted and ready to spread. Division is the only route for a non-flowering form that never sets seed.
SeedEasy
Sow indoors in late winter to early spring, or direct-sow after the last frost · Germinates in about 10-14 days; establishes over the first growing season
Sow seed indoors from late winter to early spring, or direct-sow once the last frost has passed. The seed is fine and needs light to wake up, so scatter it across the surface and press it down instead of burying it. It germinates in about 10 to 14 days and settles in over the first growing season.
DivisionEasy
Spring or early autumn · 2-4 weeks to root in
Lift an established mat in spring or early autumn and pull it apart into rooted clumps, which take hold within 2 to 4 weeks. Division is the only option for non-flowering 'Treneague', since that form never sets seed.
Myths
Roman chamomile and German chamomile are the same plant.
They look alike and both brew into tea, but they are different plants from different genera. Roman chamomile is the low, mat-forming perennial that creeps along as a fragrant groundcover. German chamomile is a taller annual that shoots up, reseeds, and is gone by winter. One spreads underfoot; the other rises and vanishes with the cold.
Chamomile is completely safe around pets because it is a soothing herbal tea.
Safe in a cup is not safe in the garden. The ASPCA lists chamomile as toxic to cats, dogs, and horses, and an animal chewing the plant can end up with vomiting, diarrhea, lost appetite, and an itchy rash. A herb that calms a person can still make a pet sick.