Herb · Asteraceae
Feverfew
Tanacetum parthenium
Set in full sun and lean, dry soil, feverfew opens white yellow-eyed daisies all summer.
Full sun
Every 7–14 days
90–120 days
USDA 5–9
Overview
Feverfew is a tough perennial in the daisy family, and through the warm months it carries small flowers built like miniature daisies: a ring of clean white petals around a flat, bright yellow center. It grows fast and asks little, which is why it slipped from old cottage gardens into beds, borders, and herb patches across cooler climates. The leaves are the other half of its look, aromatic and deeply cut into a soft, ferny outline that pins it firmly among the Tanacetum kin of tansy and the chrysanthemums.
Up close the plant earns attention twice over. Each white daisy sits on a slim stem in loose, branching sprays that make clean cut stems, and the same blooms draw pollinators to their open yellow eyes. Run a leaf between your fingers and the pungent, slightly sharp scent rises at once, the same chemistry behind the folk-medicine history caught in its name. Left alone, it sets seed heavily, so a single plant thickens into a loose stand within a season or two.
None of that texture makes it fussy. Give the ferny clumps sun, soil that drains, and a hard cut once the daisies fade, and they return each year and seed the bare gaps besides. The one habit to watch is that free seeding, which a little deadheading of the spent yellow centers keeps in check.
Care
The short version: full sun, lean and well-drained soil, and a deep drink only once the top half of the soil has dried. The spent daisies come off through the season, the ferny growth is sheared back after bloom, and the plant mostly tends itself.
Light
Feverfew opens the most white daisies in full sun and will take light partial shade. Sink it into deeper shade and the stems stretch thin and floppy and the yellow-eyed buds grow scarce, so the brightest open spot shows it off best.
Water
Once its roots take hold, feverfew runs drought-tolerant and recoils from standing wet. Soak it deeply, but only after the top half of the soil has gone dry to the touch, which falls near every 7 to 14 days, and let it dry again before the next drink.
Soil
Plain, gritty well-drained garden soil suits the ferny clumps, and they hold on even in poor, dry ground. Keep the pH between 6.0 and 7.5 and let water slip through freely, since waterlogged soil is the one thing the roots will not stand.
Temperature
Feverfew is genuinely hardy, holding its crown through cold to about -20°F (-29°C) and pushing fresh ferny growth through summer heat to 90°F (32°C). That span lets it overwinter as a perennial across a wide reach of temperate gardens.
Humidity
Plain outdoor air is all the leaves want, so no figure needs chasing. The clumps sit content in the 40% to 60% range most gardens hold, where air drifting through the foliage counts for more than the reading.
Feeding
Feverfew is a light feeder that shows better color and firmer stems on lean ground. A single thin dose of balanced fertilizer or a scatter of compost in spring is plenty, since rich feeding only swells soft, floppy growth that draws aphids.
Pruning
Pinch the spent, browning daisies through the season to keep fresh white ones coming and to curb the heavy self-seeding. When the last flowers fade, shear the ferny mound back hard for tight compact regrowth, then cut it to the ground in late fall or early spring.
Repotting
Grown in a pot, feverfew wants moving on annually or whenever it outgrows the pot. Roots winding round the rootball, growth that loses its push, and soil that dries almost the moment you water are the signs the clump needs fresh room.
Size & spacing
The clumps rise 18 to 35 inches (45 to 90 cm) tall and spread 12 to 24 inches (30 to 60 cm) wide. Allow each that much room so air slips through the ferny foliage and the roots never sit in trapped damp.
When to plant
Feverfew keeps to the seasons. The fine seed starts indoors 6 to 8 weeks before your last frost or goes straight onto spring soil, the young ferny plants move out once the cold has passed, and the white, yellow-eyed daisies open from early summer through fall.
Northern hemisphere
Southern hemisphere
Typical months for a temperate climate: start earlier in warm zones, later where spring frosts linger.
- Sow: 6-8 weeks before last frost
- Plant: Spring after danger of frost has passed
- Harvest: White daisy-like flowers with yellow centers from early-mid summer through fall; long bloom period
Hardiness
USDA hardiness zones: 5–9
Temperature: down to -29°C
Troubleshooting
Feverfew is rarely troubled, and most of what marks the leaves or thins the daisies traces to too much water, too little sun, or its own heavy seeding. Match the look below to what is in front of you, then act early while the fix is still small.
Limp, yellowing leaves over soil that stays wet
Leaves that hang limp and fade to yellow while the soil below stays wet betray root rot taking hold under the surface. Lift the plant and the roots come up brown and slack, soft to the touch and sour-smelling, with none of the pale firmness of healthy tissue. Dry the ground out and open its drainage, lift away any plant gone to mush, and reset firm-rooted divisions where water drains clear.
Fix:
- Improve drainage and reduce watering
- Remove and discard severely affected plants
- Replant healthy divisions in well-drained soil
A scatter of tiny ferny seedlings around the plant
Feverfew is a prolific self-seeder, and the ground around a parent plant fills with tiny ferny-leaved seedlings the following season. Snipping the spent daisies before their centers ripen into seed cuts that scatter off at the source. The little seedlings that do break ground lift cleanly between two fingers while their roots are still threadlike.
Fix:
- Deadhead before seed set
- Remove unwanted seedlings by hand while young
Curled, glistening leaves studded with tiny insects
Look closely at the tender new shoots and the undersides of the ferny leaves and the tiny soft-bodied bodies clustered there are aphids. They coat the surface in a sticky, glistening honeydew, and the leaf tissue puckers and curls beneath it. A hard jet of water knocks the soft clusters loose, insecticidal soap clears a thick coating, and ladybugs work through whatever clings on.
Fix:
- Spray with a strong jet of water to dislodge aphids
- Apply insecticidal soap if infestation is heavy
- Encourage beneficial predators such as ladybugs
Scattered white daisies that fade too soon
When only a scattering of white daisies opens, and they brown off quickly, the cause is usually too little sun or seed heads left to ripen on the stems. A shaded plant sets few of its yellow-eyed buds, and one carrying spent, swelling seed heads stalls fresh ones. Set it in full sun and pinch the browning daisies away, and the white flowers keep opening from early summer into fall.
Fix:
- Relocate to a full-sun position
- Deadhead spent flowers regularly to encourage continued bloom
Toxicity
Feverfew is good in the garden but not on a plate or in a pasture. The soft ferny leaves hold sesquiterpene lactones that sting the mouth and gut of cats, dogs, and horses, and the same leaf oils raise contact dermatitis and mouth ulcers on sensitive people. Pull on gloves to handle the foliage and keep pets and children from chewing it.
Toxic to
Cats · Dogs · Horses · Rabbits · Livestock · Birds · People
Cats Mild
A cat that bites into the bitter ferny leaves drools and vomits, and the upset stomach can run on to diarrhea. The sap left on its lips stings the mouth and can raise a rash where it smears against bare skin.
Dogs Mild
A dog that mouths the foliage drools and turns queasy, sometimes passing loose stools afterward. Smeared sap reddens the soft tissue of the mouth and can leave the skin it touches irritated.
Horses Mild
The sharp, bitter leaves leave a grazing horse with a sore, irritated mouth, streaming drool, and a mild turn of colic or loose manure. The bitterness is strong enough that most horses crop around it and move on.
Rabbits Caution
The same bitter sesquiterpene lactones that turn other animals off make the soft ferny leaves a poor mouthful for rabbits, so keep the plant clear of the hutch and out of any pile of cut greens.
Livestock Caution
Cattle, sheep, and goats nose past the bitter foliage, but its compounds gnaw at the gut if hunger forces the leaves down, so it makes no kind of fodder.
Birds Caution
Nothing reliable marks the aromatic, oily leaves as safe for pet or backyard birds, and the irritant oils warn against them, so keep the plant well back from cages and aviaries.
People Caution
The leaf oils can raise an itchy contact rash on sensitive skin, and a chewed fresh leaf often leaves the mouth sore and ulcerated. Slip on gloves before you cut the stems and rinse the oils from your hands afterward.
Wear gloves when handling foliage; sesquiterpene lactones can cause contact dermatitis in sensitive people, and chewing fresh leaves can cause mouth irritation and ulcers.
Helpline numbers
United States
ASPCA Animal Poison Control: (888) 426-4435 (fee applies)
Poison Control: (800) 222-1222
Canada
Poison Centres: 1-844-764-7669
Varieties
Past the plain white daisy, a few selections stand out by their flowers or their leaves, set apart by doubled petals or by foliage that glows rather than greens.
'Aureum' (Golden Feather)
Its draw is the foliage itself, a bright chartreuse-gold rather than green, so it is grown for the glow of the leaves over the flowers.
'Flore Pleno'
Its flowers drop the open daisy face entirely for tight, fully double white buttons crowded edge to edge with petals.
'Snowball'
Its blooms swell into rounded white pompons, a dense double form whose layered petals read almost like a small chrysanthemum.
How to propagate
Feverfew increases with almost no effort, from its fine light-hungry seed or from a split clump, and it scatters its own seed thickly on top of that.
SeedEasy
Sow indoors 6-8 weeks before last frost or direct sow in spring; surface sow as seeds need light to germinate · Germination in 1-2 weeks; flowering plants within the first season
The fine seed grows readily, started indoors 6 to 8 weeks before your last frost or scattered straight onto spring soil. Lay it on the bare surface rather than burying it, since the tiny seed needs light striking it to break, and the first green threads push up in 1 to 2 weeks. Plants raised this way carry their white daisies in the first season, and because it self-sows so freely, the small volunteers lift easily for moving while young.
DivisionEasy
Spring or early fall · Several weeks to re-establish in the season of division
Prising apart a mature clump in spring or early fall freshens a tired crown and yields pieces identical to the parent. Ease the clump from the ground, pull it into rooted, leafy sections, and firm each back into soil. The divisions knit in over a few weeks and carry on growing through the same season.
Myths
Feverfew gets its name because it reliably cures fevers.
The name does trace to the Latin febrifugia, meaning fever reducer, a clue to how it was once seen. Both the old traditional use and the modern studied use, though, settle on headache and migraine rather than fever. It was never a dependable fever remedy, and the name is just a survival from old folk medicine.