Fleabane, the small white or pinkish daisy that pops up in lawns, roadsides, and garden edges, is far more useful than its weedy look suggests. Its real value goes mostly to wildlife rather than to people. The name promises a flea killer, and the plant has a long folk-medicine record, but both claims are much thinner than its role in feeding insects.
How Fleabane Feeds Bees and Butterflies
Each fleabane flower head is tiny, which lets the smallest native bees and beneficial insects reach its pollen and nectar.1Gurneys. What Can I Plant to Support Pollinators? Small bees, pollinating flies, and sometimes small parasitic wasps come to feed on the nectar.2suburbanhobbyfarmer.com. Do Wildflowers Attract Beneficial Insects? Absolutely! Try These Some of those visitors are garden helpers, because parasitic wasps lay their eggs in many pest insects.
Fleabane flowers early in the season, when other pollen and nectar sources may be scarce.3Gurneys. What Can I Plant to Support Pollinators? Its flower clusters keep feeding pollinators well into fall.4authorvbray.com. Fleabane: A Native Wildflower for Pollinators
What looks like one flower is really a cluster of many tiny florets, so a small insect finds many feeding spots in a single landing. The flat, open heads let short-tongued flies and small bees reach nectar without probing a deep tube, as deeper flowers require. Because fleabane often grows in loose patches, a bee can move from head to head with little flying.
Fleabane is also a host plant, meaning one whose leaves a butterfly or moth caterpillar must eat to grow. Philadelphia fleabane is the host plant of the northern metalmark butterfly.5authorvbray.com. Fleabane: A Native Wildflower for Pollinators In western states, the fleabane Erigeron speciosus feeds northern checkerspot caterpillars.6authorvbray.com. Fleabane: A Native Wildflower for Pollinators Several fleabanes feed the caterpillars of the lynx flower moth, a harmless moth found east of the Rockies whose adults pollinate flowers.7Gurneys. What Can I Plant to Support Pollinators? This makes sense because fleabane belongs to the aster family, along with goldenrod, coneflower, and sunflowers, a group many caterpillars depend on.8authorvbray.com. Fleabane: A Native Wildflower for Pollinators
Adult butterflies can sip from many kinds of flowers, but their caterpillars often eat only a few plant types. Without those plants, a yard can attract adult butterflies and never raise new ones. Chewed leaves on fleabane may mean caterpillars are using it, not that the plant is sick, and leaving them be is the trade-off for supporting a full life cycle. Insecticides sold for lawns and gardens kill caterpillars and small bees along with pests, so a fleabane patch gets much less value in a yard that is regularly sprayed.
Using Fleabane in a Garden
Some fleabanes are sold as tough garden plants. Several are recommended as drought-tolerant plantings, including seaside fleabane, sometimes called beach aster.9San Francisco Public Works. San Francisco Sidewalk Landscaping: Recommended Drought Tolerant Plant List Beach aster grows only about 8 inches tall, tolerates clay soil, and is short-lived.10San Francisco Public Works. San Francisco Sidewalk Landscaping: Recommended Drought Tolerant Plant List Mexican daisy, another fleabane, grows to about 1.5 feet tall and 3 feet wide as a perennial.11San Francisco Public Works. San Francisco Sidewalk Landscaping: Recommended Drought Tolerant Plant List It can be invasive, though, and should be cut back hard in fall.12San Francisco Public Works. San Francisco Sidewalk Landscaping: Recommended Drought Tolerant Plant List
Because the common name covers many different plants with different heights and habits, check the tag for the exact species before buying. Native fleabanes suit a wildlife garden best, while garden-center types such as Mexican daisy are chosen mostly for looks and tolerance of dry conditions. Even a drought-tolerant fleabane needs regular watering for its first season while the roots establish. After that it can usually be left alone.
For a spot, pick somewhere sunny, since most fleabanes bloom best in full sun. Use the low beach aster along path edges and Mexican daisy where it can spill over a wall. Group plants together so small pollinators find them easily, and plan to replant the short-lived types every few years.
Wild fleabanes like Philadelphia and daisy fleabane often arrive on their own in lawns, edges, and disturbed ground. Letting a patch bloom in a corner or meadow strip gives pollinators food at no cost. Cutting flowers before they go to fluffy seed keeps them from spreading through beds.
That seed is the main challenge. It is lightweight and blows away on fluff, so one neglected patch can seed beds well beyond where it started. Deadhead as flowers fade but before the heads turn fluffy and white, since seeds can mature quickly after that. If you want some seedlings but not too many, leave a few stalks standing in one chosen corner and clip the rest. Thick mulch or dense neighboring plants make it harder for seedlings to settle in bare soil, which is where they usually start.
To remove plants you don’t want, pull young ones by hand when the soil is moist and the roots come out whole. Mowing or deadheading after the main bloom means fewer plants next year.
To tell fleabane from oxeye daisy, look at the petals: fleabane has many narrow, threadlike petals around a yellow center, while oxeye daisy has fewer, broader ones. Its flowers are often under an inch across and come in loose clusters.
Does Fleabane Really Repel Fleas
The name fleabane comes from Old English and refers to the plant’s smell, which was supposed to drive off fleas.13USDA Natural Resources Conservation Service. Philadelphia Fleabane Plant Guide People hung it from the eaves, stuffed it into pillows and mattresses, or burned it to ward off insects.14UF/IFAS Extension Sarasota County. What Is That Lawn Ornament? A Daisy That Keeps Away Fleas? Daisy Fleabane! Like wolfsbane and henbane, the “bane” in its name reflects a folk belief that the plant could kill or repel pests.15Brooklyn Botanic Garden. Weed of the Month: Fleabane
There is little evidence that fleabane works as an insect repellent the way it was traditionally used.16Brooklyn Botanic Garden. Weed of the Month: Fleabane Concentrated oils from several fleabane species have shown repellent and larva-killing effects in lab tests, though.17PubMed Central. Compositional Variability of Essential Oils and Their Bioactivity in Native and Invasive Erigeron Species Concentrated oil is far stronger than dried leaves, so those results don’t show that a bundle of dried fleabane protects a pet or bed.
Those lab tests exposed insects to a measured amount of oil in a small space, very different from a room or a pet. Oil strength also differs between species, plant parts, and extraction methods, so a result for one fleabane doesn’t carry over to the one in your yard.
Most fleas in a home aren’t on the pet. Eggs, larvae, and pupae sit in carpet, bedding, and floor cracks, so treating only the animal rarely ends the problem. Eggs fall off pets and hatch where the animal rests, which is why cleaning its sleeping area matters as much as treating the animal. Ask a veterinarian for a proven flea treatment rather than relying on herbs, wash pet bedding often, and vacuum carpets to remove eggs. Don’t put homemade plant oils on pets, because concentrated oils can irritate or harm animals.
Fleabane as Medicine
Philadelphia fleabane was traditionally used as an astringent, to tighten tissues, and as a diuretic to increase urine.18United States Department of Agriculture Natural Resources Conservation Service. Philadelphia Fleabane Plant Guide It was also used as an aid for the kidneys and for gout.19United States Department of Agriculture Natural Resources Conservation Service. Philadelphia Fleabane Plant Guide A traditional use shows what people believed, not that it worked or was safe at the doses used.
Lab work is more specific. An extract of daisy fleabane roots reduced swelling in rats and calmed inflammation signals in cells.20PubMed Central. Roots of Erigeron annuus Attenuate Acute Inflammation as Mediated with the Inhibition of NF-κB-Associated Nitric Oxide and Prostaglandin E2 production A water extract of daisy fleabane cut histamine, the chemical behind itching, in human cells grown in the lab.21PubMed Central. Pyromeconic acid-enriched Erigeron annuus water extract as a cosmetic ingredient for itch relief and anti-inflammatory activity Researchers are now testing it as a skin-care ingredient for itch relief.22PubMed Central. Pyromeconic acid-enriched Erigeron annuus water extract as a cosmetic ingredient for itch relief and anti-inflammatory activity Fleabane leaves also contain plant compounds that act as antioxidants in lab tests,23PubMed Central. Evaluation of Phytochemistry, Toxicity and Radical-Scavenging Capacity of Two Erigeron Species (E. annuus (L.) Pers. and E. strigosus Muhl. ex Willd.) Extracts and extracts have been tested against bacteria.24London Met Repository. Phytochemical and biological investigation of erigeron annus (L.) Pers for antimicrobial activity and potential DNA gyrase inhibitors
These findings are early signs, not treatments. The rat study measured swelling in a controlled setting, which isn’t a test of a human condition. The itch result came from human cells in a dish, so it shows the extract can affect histamine there, not that it relieves itch on skin. Cells in a dish get the extract directly, without digestion or the liver changing it, and rats can respond differently from people. Antioxidant activity in a test tube is common among many plants and doesn’t by itself mean a plant improves health when eaten. Antibacterial tests show an effect in a lab, a long way from treating an infection in a person.
None of these results come from trials in people, so they don’t show a safe or effective dose. Talk with a doctor before using fleabane teas or extracts, especially for kidney problems or gout.
Supplements and teas may not say which fleabane species they contain, and strength varies because no standard dose exists. A diuretic effect could matter if you already take water pills or have kidney disease. Tell a doctor or pharmacist about any herbal tea you drink, because plant products can interact with medicines even when they seem mild. Don’t swap fleabane tea for a treatment prescribed for gout or kidney trouble, since those conditions can worsen without proper care. Skip fleabane preparations if you are pregnant, nursing, or giving anything to a child, since no safety information exists for those situations.
Is Fleabane Safe to Touch and Handle
Plants in the aster family can cause itchy skin rashes in some sensitive people. In allergy patch tests in children with this kind of rash, though, a common fleabane gave no reactions.25JAMA Dermatology. Compositae Dermatitis in Childhood The test covered one common fleabane in children who already had a rash, so it doesn’t guarantee every fleabane is safe for every person.
People allergic to ragweed may sneeze around many aster-family plants in bloom. Wear gloves and long sleeves when pulling large amounts, and wash your hands before touching your face after weeding. See a doctor for a rash that spreads or blisters.
Most garden rashes come from other plants, such as poison ivy or nettles, so a rash after weeding isn’t automatically fleabane’s fault. A plant allergy rash is often itchy and red and may appear where the plant touched skin, sometimes a day or two after contact, though other rashes can look similar. If you suspect a plant, note what you handled and when, which helps a doctor work out the cause.
Small nibbles by children or pets are not known to be dangerous, but fleabane isn’t a food plant. Keep homemade fleabane oils away from both.
Horseweed and Other Fleabanes That Are Problems
Horseweed, also called Canada fleabane, is a common weed of fields and gardens. In Michigan farm samples, 60% of horseweed populations resisted glyphosate, the ingredient in many common weedkillers.26Cambridge University Press. Agronomic predictors of herbicide-resistance in horseweed (Erigeron canadensis) for proactive management in Michigan Also, 35% resisted 2,4-D and 20% resisted dicamba, other common lawn and farm weedkillers.27Cambridge University Press. Agronomic predictors of herbicide-resistance in horseweed (Erigeron canadensis) for proactive management in Michigan Spraying may not kill horseweed, so pull or mow it before it seeds.
You can spot horseweed as a single tall stalk, often head high, crowded with narrow leaves. Its flowers are tiny and plain, without the showy petal ring of daisy fleabane. Pull it young, because each plant releases huge numbers of wind-blown seeds, and the taproot of a large plant is hard to remove whole. Mowing before the flower stalks open stops seed production, but cutting too late can still leave seed-bearing stalks.
Not every fleabane is a weed. Zuni fleabane, found only in a small area of the Southwest, has been listed as threatened since 1985, mainly because of surface mining.28USGS. A habitat suitability model for testing and refining the range of Zuni fleabane, a threatened plant species Leave wild plants alone in natural areas.
Don’t count on fleabane to clean up bad soil either. Daisy fleabane did not pull up enough heavy metals to clean polluted soil in a field test,29Agronomy Research. Assessment of wild plants for phytoremediation of heavy metals in soils surrounding the thermal power station so growing it won’t detox garden soil near roads or old industry. If contamination is a concern, test the soil and use raised beds.