Garlic Mustard (Alliaria petiolata)

The bane of woodlands!!! This non-native plant can quickly overrun a woodland or savanna with a “take no prisoners” approach. When we purchased our land in 2005, the remnant oak-hickory woodland was a garlic mustard monoculture. We began in earnest to remove it.

Working smarter rather than harder, I use knowledge when I need workarounds. Determining the best answer for my goals and my unique piece of land requires a hybrid system of academic studies, biological sciences, and a dash of anecdotal evidence. I’m sharing in hopes it helps you, too.

Helpful Garlic Mustard Facts

  • Can self pollinate (Anderson et al 1996, Chapman et al 2012)
  • Seedbank persistance can be 3 years (Nuzzo 1991)
  • Seeds dispersed via foot traffic, animal fur, and water movement and not by wind (Cavers et al 1978)

Management Requires a Combination of Tools

Garlic mustard greens up in spring early, before many of the native plants. This is convenient.  Management can be timed so no collateral damage to spring ephemerals occur.


When we began controlling garlic mustard, we sprayed rosettes with 2% glyphosate in spring and again in the fall. Pulling those we missed was necessary follow up. In the first 6 years, we substantially decreased the infestation. But we began to notice deformed garlic mustard plants; they were growing, flowering, and appeared to be setting seed. I do not know if these seeds were viable. Were the plants becoming resistant to glyphosate? In 2011, we switched herbicides to Progeny® and are having better success. Whatever herbicide you choose, read and follow the label directions.

Hand pulling

There’s good news! “Uprooting plants at the flowering stage prevented production of any viable seed, while early- and late-fruiting plants were still able to produce viable seed (Chapman et al 2012).

The study further demonstrated height and seed production were correlated; 13” or shorter plants had low seed viability and 16” or taller plants had high seed viability (Chapman et al 2012). The plant’s phenological stage is also a significant “tell;” early fruiting plants (silenes visible but flowers still attached) had significantly more viable seed than late-fruiting plants (silenes only) (Chapman et al 2012).

Mowing or weed whacking

Mowing is effective for 2 reasons. Cutting at the ground level “resulted in 99% mortality and reduced seed production to virtually zero” (Nuzzo 1991). Cutting around 4” high had 74% mortality and 98% seed reduction (Nuzzo 1991, Chapman et al 2012). Mowed plants late in the season typically do not regrow after mowing (Cavers et al 1978). Some may appear to resprout, but they lack the stored resources after bolting and will not produce viable seed (Chapman et al 2012). Knowing the biology of this plant helps us to know mowing is effective.

We weed whack the larger patches as a triage method when we don’t have time to pull the plants before they set seed.


There are a couple ways to use fire – prescribed burns and flame weeding.

Prescribed burns can be effective at the proper intensity.  “Low-intensity fire did not affect the incidence of A. petiolata  but mid-intensity reduced rosettes” (Nuzzo 1991). In a woodland setting where the fuels are leaf litter, a general way to think of fire intensity is to think of humidity. A low-intensity fire would occur when there was high humidity, either in the air or in the leaf litter – perhaps morning or evening.

Flame weeding uses a backpack flame weeder works similar to herbiciding — a particular plant is targeted and zapped. Fire wandering away from the target is something to be prepared for but if done when humidity is high or when morning dew remains.


Grazing isn’t an effective tool for garlic mustard control. The plant contains a chemical that deters herbivory (Chapman et al 2012) and can add an unpleasant flavor to milk from animals grazing this (Cavers et al 1978). Unfortunately, we can’t depend on deer to graze it either; they find it “completely inedible” (Kalisz et al 2014). And more unfortunate, where deer are abundant so is garlic mustard because they depress native plants with their grazing.

For more info on prescribed fire, in general.

Combine Management Tools

Using different management techniques and tools ensures biodiversity and can save resources! As much as we all want a single “magic bullet” there isn’t one. Mix and match these management tools and planning follow up ensures success.

The native plants returned once we controlled the garlic mustard. Plants that we now enjoy that were suppressed include shooting star, Indian pipe, bellwort, wild geranium, wood anemone, solomon’s seal, false Solomon seal, and yellow pimpernel to name a few. Diversity is the key to a good healthy environment.

Below is a picture of our “purple carpet” of wild geranium. When these bloom, the woods have a wonderful light perfumely aroma!

Wild geranium in woods


Anderson, Roger C., Dhillion, Shivcharn S. and Kelley, Timothy M. (1996), Aspects of the Ecology of an Invasive Plant, Garlic Mustard (Alliaria petiolata), in Central Illinois. Restoration Ecology, 4: 181-191.

Cavers, Paul B., Heagy, Muriel I., & Kokron, Robert F. (1979). The biology of canadian weeds.: 35. Alliaria petiolata (M. Bieb.) Cavara and Grande. Canadian Journal of Plant Science59(1), 217-229.

Chapman, Julia I, Philip D. Cantino, Brian C. McCarthy. 2012. Seed Production in Garlic Mustard (Alliaria petiolata) Prevented by Some Methods of Manual Removal.” Natural Areas Journal 32(3): 305-315.

Kalisz, Susan & Spigler, Rachel & Horvitz, Carol. (2014). In a long-term experimental demography study, excluding ungulates reversed invader’s explosive population growth rate and restored natives. Proceedings of the National Academy of Sciences of the United States of America. 111. 10.1073/pnas.1310121111.

Nuzzo V. 1991.  Experimental control of garlic mustard [Alliaria petiolata (Bieb.) Cavara & Grande] in northern Illinois using fire, herbicide, and cutting. Natural Areas Journal 11: 158-167.

Gypsy Moth Treatment

If you received a notice about gypsy moth spraying in your county, you can check to see the target sites with the Department of Agriculture (DATCP) interactive map.

What is the killing agent?

Bacillus thuringiensis serotype kurstaki (Btk) is a group of bacteria which makes it a biological control agent. This bio-control agent is different from those where a non-native insect is brought in to kill off a non-native plant. All bio-control measures need a healthy dose of skepticism applied to them — two non-natives don’t make a native. Since Btk is commonly found in our soils, it does not introduce a foreign entity into our ecosystems.

How does Btk work?

I went in search of how Btk does the “dirty deed.” Btk is not a contact insecticide; the insect must ingest it. It is a stomach poison and will only effect the larval feeding stage (i.e., when it is a caterpillar). Andrea Diss-Torrance, Invasive Forest Insects Program Coordinator for the Wisconsin DNR, tells me that “among moths and butterflies, the effect can vary: about a third of species tested are sensitive, about a third are not [a]ffected at all, and about a third have an intermediate level of sensitivity. Btk is degraded by sunlight and very sensitive caterpillars, such as the Eastern tent caterpillar, are no longer [a]ffected about 11 days after application to foliage”(Andrea Diss-Torrance, personal communication, May 3, 2018).

“When Btk is ingested by a susceptible caterpillar, the highly alkaline environment of the caterpillar’s gut triggers the Btk bacterium to release a crystalline protein called an “endotoxin” that poisons the insect’s digestive system. The endotoxin acts by killing cells and dissolving holes in the lining of the insect’s gut. When a mixture of food, Btk spores, and digestive juices leaks through these holes into the insect’s blood, it causes a general infection that kills the caterpillar. Humans and other mammals have highly acidic environments in their stomachs that destroy Btk before it causes infection” (Ellis 2018).

Two types of Btk mixtures

There are two commercial brands of bio-control mixtures being used against the Gypsy Moth: Foray48® and Gypchek®. The DNR determines which to use based on insects listed in the Natural Heritage Inventory. I have repeatedly expressed my concern with this methodology. Current lists for Lafayette County will be insufficient to ascertain if classified species exist because our county is incredibly undersurveyed for insects (and plants for that matter). I suspect few counties have insect surveys covering the county.

Christopher Foelker, Gypsy Moth Unit Supervisor for DATCP, tells me Gypchek® is used in habitats having known T&E species that are in a vulnerable life stage during the treatment times. (Christopher Foelker, personal communication, May 3, 2018). DATCP considers Gypchek® to be less effective than Btk because it deteriorates quickly and has a much shorter window of efficacy. It is a viral insecticide that is specific to the gypsy moth but it iscostly to produce and there are limited amounts. It is manufactured by raising and infecting gypsy moth caterpillars with a virus (NPV-gypsy moth). These infected caterpillars are ground up and suspended in a liquid solution. This solution is Gypchek® and it is applied to the tree canopy.

Since it is a limited resource, state and federal governments agree to use Gypchek® only where rare species are known and not on every area proposed for Btk treatment. Unless a T&E insect is known, Foray48® is used.

Foelker says all the DATCP treatment plans are reviewed by the US Fish and Wildlife and US Forest Service for any potential effects on T&E species. They present any concerns for areas these species might be impacted.

Who else is affected?

Since I seldom take info from just one source, I continued my sleuthing on this topic. Jay Watson, who works in the Bureau of Natural Heritage Conservation,confirmed my suspicions, “Really, the impacts from Btk on other insects is very poorly understood.  I don’t know of any research that has looked at what impact this might have on insects like bumble bees.” (Jay Watson, personal communication, May 3, 2018). He specifically mentioned bumble bees because of our recently discovered rusty-patched bumble bee on our property.

There are two sides to every issue; this one is no different. Diss-Torrance stated, “the effect, or in this case non-effect, of Btk on a wide range of other creatures is very well known as this bacterially based insecticide has been used extensively in agriculture and forestry since the ‘80’s.”

In general, sunlight and other microbes destroy Btk applied to foliage within three to five days, so Btk does not multiply or accumulate in the environment (Ellis 2018). Yet, in a 1998 study, Btk was added to different types of soil in order to determine how the type of soil affected the persistence and concentration of Btk. The results of the study showed insecticidal activity started to decline after a month in one soil, while in another, toxicity was high after six months. The authors of the study noted that even though Btk is considered non-toxic to non-target species, the accumulation and persistence of the Btk toxins could eventually lead to environmental hazards or the selection of Btk-resistant lepidopterans (Wikipedia 2018).

The EPA has studies demonstrating a small level of toxicity to certain fish, a slight toxicity to honey bees at high level doses, and “practically non toxic” at low level doses. It is slightly toxic to the convergent lady beetle (Hippodamia convergens) (EPA 1998). Caterpillars that become ill or die after ingesting Btk are not considered dangerous to birds or other animals that feed on them (Ellis 2018).

I wasn’t thinking there would be a moral to this story when I began researching it, but I believe that there is. The value of citizen science is priceless and saves lives. Wisconsin DNR’s decision-making about gypsy moth treatments relies solely on the information at the Natural Heritage Inventory. The information behind many decisions that mitigate impacts to our natural community and our T&E community originates from citizen scientists.


Ellis, Jodie A. (04 May 2018). Exotic Insects Education Coordinator Department of Entomology, Purdue University. Retrieved from

Entomological Society of America. (May 2018). Is Bt safe for humans to eat?

Environmental Protection Agency. (1998). EPA 6452 Fact Sheet. Retrieved from

Tobin, Patrick C. and Andrew M. Leibhold. “Gypsy Moth” in Encyclopedia of Biological Invasions. (Los Angeles: University of California, 2011): 298-304.

Wikipedia. (04 May 2018). Retrieved from


Non-native invasive species do incredible damage to our native ecosystems. They exclude our native species — insects, plants, animals and other biota – reducing biodiversity, reducing crop yields, reducing recreational enjoyment of our waters, and lowering land values. 

While awareness of the damage invasives do has expanded, it isn’t always clear what we as individuals can do. With the technology of smart phones and tablets, there is a fun new app available to help map locations of invasions. This app is the Great Lake Early Detection Network (GLEDN) and has been developed specifically for our area.

It’s an easy-to-use and intuitive app. Wisconsin First Detector Network (WIFDN) has videos to assist with downloading the app and getting started. Once the app is downloaded, you can choose from these categories: aquatics, birds, crustaceons, diseases, fish, grasses, herb/forbs, and insects.

Embedded in the app is a fact sheet about each species. Each fact sheet includes photos, species descriptions, currently mapped locations of infestations and an explanation of why it’s an ecological threat.


Data is collected with a single point or with a polygon. The larger infestations are noted with a polygon which can be drawn to the exact shape of the invasion. If you use the polygon option, the app calculates the size of the infestation. Each record automatically ascertains the GPS points using the WSG84 datum format.

GLEDN, Invasives

Each record is verified so a photo is required. This verification process ensures the credibility of the records.

You can create your own species list or use one generated for the Great Lakes region. You also have the choice to use the scientific name or the common name. You can note the habitat types and note the infestation’s density – low, medium, or high.

Once finished collecting the data, each report needs to be specifically submitted. Until it is, the info remains stored in your phone or tablet. This is a valuable option because you don’t need to use the data on your phone plan to submit the reports; you can wait until you have a wi-fi connection. Reports can be uploaded all at once or one at a time. The biggest downfall is there is no spinning circle to alert you that the upload is in progress. Patience is required. You will see a message on your screen when the upload is complete.

GLEDN can assist land managers especially with large tracts of land. One can decide if any and all species will be reported or only a select few. Once GLEDN has assisted with the documentation, management activities on these patches of invasives can be tracked with the Invasive Species Management Tracking System (ISMTrack). The annual cost for the management software is very reasonable. For a private landowner using ISMTrack on their property, the fee is $25/year. For non-profits, the cost is $50/site or $200 for 5+ sites. Contact WIFDN for training and additional information.

Data from this app is used inconjunction with EDDMaps (Early Detection & Distribution Mapping System), a national database of invasive species. Once the data is collected using GLEDN, downloading toEDDMaps provides mapping capabilities without needing GIS software knowledge. Additionally, as a national database, it allows us to see trends and species movement. 

GLEDN, Invasives

Common St Johnswort – Hypericum perfolatum

Common St Johnswort (Hypericum perfolatum) is native to Europe, Asia, and Africa. It is also known as Klamath weed, goatweed, and dotted St Johnswort (because the leaves are dotted). Introduced as a garden ornamental, it was discovered in 1793 in Pennsylvania. How many invasives can you name that were introduced in this manner? Seven US states consider is a noxious weed. As with many non-natives, Common St Johnswort has no substantiated value for wildlife as food or as cover. In fact, it is dangerous to livestock and birds do not feed on the fruiting parts either.

Common St. Johnswort contains hypericin

The danger to livestock is because the plant contains a chemical called hypericin. This chemical creates light sensitivity to lightly pigmented areas of livestock  – the mouth, nose, ears, and udders. Sheep, cattle, horses, and goats are susceptible; goats are more resistant than others. Their skin blisters, they lose hair, and generate a fever; they experience rapid pulse and respiration rates, increased salivation and diarrhea. Affected animals may die of dehydration or starvation because of swelling and soreness of the mouth.


Hypericum perfolatum
Common St Johnswort, Hypericum perfolatum
Common St Johnswort, Hypericum perfolatum

Photo on right: Common St Johnswort, Hypericum perfolatum, without blooms.

Photo above: Close up of the leaves of Common St Johnswort, Hypericum perfolatum. Notice the dots on the leaves.

Where it Prefers to Grow

Common St Johnswort likes full or partial sun and grows in a variety of soil types. It is found in grasslands and forested areas in North America. It does not like competition and establishes quickly where disturbance has created bare soil (e.g. animal scratches, burned areas, and new plantings). It also favors high soil moisture and wet seasons. Bosy and Reader (1995) found that a covering of grass litter significantly reduced germination and shoot extension.

Physiology of Common St. Johnswort

A single Common St Johnswort plant can have many aboveground vegetative parts strung together   with a system of vertical and lateral roots. This root system is extensive. It starts by putting down a taproot that extends 2 to 5 feet deep. The lateral root growth is shallow, usually 0.5 to 3 inches below the soil surface. In autumn and spring or following plant injury, these lateral roots produce buds from which new plants develop. These new plants can be as far as 3 feet from the parent plant with sprouting in between. Each seedling eventually matures and becomes independent, developing up to 30 stems per parent plant. This massive root system with its numerous young sprouts create an impenetrable mat near each parent plant. 

Common St Johnswort, Hypericum perfolatum
Common St Johnswort, Hypericum perfolatum

Notice the large taproot of this well-established plant.

This is a younger plant. Notice the offset of the taproot and all the little brown rootlets.

Common St Johnswort, Hypericum perfolatum

Lots of rootlets and seedlings arising from this taproot!

Common St Johnswort, Hypericum perfolatum

The lateral roots extend at relatively long distances and along these seedlings will arise. It’s easy to see how these can take up space in your prairie and outcompete other plants.

Common St Johnswort, Hypericum perfolatum

More root structure examples.

Common St Johnswort, Hypericum perfolatum

A young plant with a developing tap root.

Common St Johnswort, Hypericum perfolatum

A young adult plant without a fully formed tap root.

Seedlings of Common St. Johnswort are very small and grow slowly compared to seedlings of other plants. This slow growth makes seedlings susceptible to competition for light, nutrients, space, and moisture from not only the mature parent plant, but independent Common St. Johnswort plants and other species. Drought will severely reduce seedlings but when moisture levels are favorable an abundance of seedlings can be found.


Reproduction occurs via self-pollination as well as pollination by a variety of insects. Regeneration also occurs via vegetative propagation and is stimulated by disturbance (e.g. grazing, fire, mowing). Vegetative propagation can occur from the root fragments, the root crown, or sprouting from the lateral roots.

Common St Johnswort does not flower or produce seeds until the 2nd year. That is not much relief since estimates of seed production range from 15,000 to 34,000 seeds per plant with an average of 23,350 seeds (Tisdale et al. 1959). Variation in seed production is a function of site factors, seasonal growth conditions, and the level of disturbance and competition. That multiplies quickly when considering each plant can have 30 stems and each stem can contain 25-100 flowers! The seeds are produced in pods or capsules, which average to about 73 pods per plant (Compton et al. 1988).

Common St Johnswort, Hypericum perfolatum

The seed pods are forming.

We know from laboratory experiments and field studies that Hypericum seeds persist in the soil for many years. Some results suggest seeds of Hypericum species remain viable in the soil for more than 50 years (War et al. 1994). While germination is highest when the seeds are in the top half inch of the soil, they will germinate when they are 3 inches deep (Tisdale et al. 1959). Germination can occur in spring, fall, or winter and takes an average of 1 to 2 weeks. I have found young seedlings and plants in full bloom alongside plants setting seed.

Dispersal can be by wind, water, humans, and other animals. The pod or seed capsule has a sticky exudate which aids in two ways. It adheres the seed to something or someone and doesn’t allow the seed to germinate until this coat is removed by wear or water. Viability after storage is high; 94% germination after 5 years and 50% germination after 16 years.

How to Control Common St Johnswort

As with all non-natives and invasives, control must be sustained. Infested areas must be monitored each year. With this particular plant, keeping disturbance to a minimum is helpful until the infestation can be brought under control.

Cutting and mowing are ineffective as management methods for Common St Johnswort since sprouting may occur immediately after crown removal or defoliation. Mowing also negatively affects surrounding plants that could outcompete with it if allowed to grow and set seed. As with most other invasives I’ve been researching (i.e. Ox-eye daisy, spotted knapweedQueen Anne’s lace), burning could increase the density and vigor of these plants, thereby increasing the area of their infestations. If you use prescribed fire for other management reasons, be sure you schedule time for the requisite follow up.

I have found mechanical removal to be the most effective. It does leave soil disturbance but if done early enough in the spring, this provides space for the native plants. One can always overseed these areas in the fall, too. Because any root segments left on the soil surface could sprout, be sure to carry your pulled plants out.

Coupled with hand pulling, if I break off the taproot or leave a portion of a lateral root exposed, a spritz of 20% triclopyr in bark oil will ensure a new plant will not sprout. If the clump is large, to mitigate soil disturbance, I will lop it off at the base and spritz it with the tricolpyr mixture. Metsulfuron is another chemical that will kill the plants. It is usually applied foliarly and is successful with large clumps. The small leaves of first-year plants make foliar spraying difficult to do without a good deal of collateral damage; hand pulling is best for these. 

Persistence does pay off! We have been able to reduce the number of these plants at Driftless Prairies with annual monitoring and treatment.


Bosy, J. L.; Reader, R. J. 1995. Mechanisms underlying the suppression of forb seedling emergence by grass (Poa pratensis) litter. Functional Ecology. 9(4): 635-639.

Crompton, C. W.; Hall, I. V.; Jensen, K. I. N.; Hilderbrand, P. D. 1988. The biology of Canadian weeds. 83. Hypericum perfolatum L. Canadian Journal of Plant Science. 68(1): 149-162.

NRCS Plant Guide (Accessed 10 Jun 2016)

Rice, Barry Meyers; Randall, John. 2004. Weed report: Hypericum perforlatum–St. Johnswort, Klamath weed. In: Wildland weeds management and research: 1998-99 weed survey. Davis, CA: The Nature Conservancy, Wildland Invasive Species Program. 7 p. On file with: U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory, Missoula, MT.

Tisdale, E. W.; Hironaka, M.; Pringle, W. L. 1959. Observations on the autecology of Hypericum perfolatum. Ecology. 40(1): 54-62.

Warr, Susan J.; Kent, Martin; Thompson, Ken. 1994. Seed bank composition and variability in five woodlands in south-west England. Journal of Biogeography. 21(2): 151-168.

Zouhar, Kris. 2004. Hypericum perfolatum. In: Fire Effects Information System, [Online]. U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory (Producer). Available: [2016, June 10]. (Accessed 10 Jun 2016)

Oxeye Daisy – Leucanthemum vulgare

Oxeye daisy (Leucanthemum vulgare) is a perennial, herbaceous, non-native plant growing 1 to 3 feet tall with showy white flowers. It was introduced from Europe as an ornamental plant and as seeds contaminating cereal crops. It has spread profusely across the world and is a non-native in 40 countries and every state in the U.S. Oxeye daisies survives in a wide variety of soil types, climates, and other environmental conditions. Frost and drought do not affect this plant.

The previous botanical name, Chrysanthemum leucanthemum, means “gold flower white flower.” The current name, Leucanthemum vulgare means “common white flower.” It also has several common names: bull daisy, button daisy, dog daisy, field daisy, goldens, marguerite, midsummer daisy, moon flower, and white weed.

Oxeye Daisy, Leucanthemum vulgare

A side view of oxeye daisy – not a view I see very often unless it’s after I pulled it!

Oxeye Daisy, Leucanthemum vulgare

A top down view of Oxeye daisy. Notice how unique the leaves are.

These are easy plants to recognize. Their alternate clasping leaves are toothed and become narrower toward the top. The basal leaves are spoon-shaped.  The white flowers are usually what catches my attention but very unique leaf pattern does as well when I’m doing my early spring spot check. 

Oxeye Daisy, Leucanthemum vulgare

A close up of the leaves of the Oxeye daisy.

Oxeye Daisy, Leucanthemum vulgare

This shows how all the first year rosettes are clustered at the base. These and the small seedlings are critical to remove.

Oxeye Daisy, Leucanthemum vulgare

A close up of the spoon-shaped basal leaves of Oxeye daisy.

Their Growth Habit

Oxeye daisy spreads by seeds, by rhizomes, and by adventitious roots. The roots are shallow and grow rapidly, forming a dense mat that leaves no space for the native plants. If you pull up a large clump, it creates a good deal of soil disturbance as well as a shallow hole. Often when hand pulling, the individual stems easily break off from the main clump. If you leave one stem, you’ll be back again! 

Oxeye Daisy, Leucanthemum vulgare

Notice how the stems curve away from the main root system.

Oxeye Daisy, Leucanthemum vulgare

Here’s a view of the adventitious roots. The lateral stems that touch the ground develop their own root system. Notice how far away from the main stem the one on the right has grown.

Oxeye Daisy, Leucanthemum vulgare

Another view of the incredible root creating system of Oxeye daisy.

Oxeye daisy has 2 growth periods – spring and fall — and germination occurs throughout the growing season. The report from the Washington State Noxious Weed Control Board states 90-95% will germinate at 68 degrees F. Fall is when most seedlings establish.  First year plants will remain in the rosette stage until after a cold winter which initiates blooming. It is this rosette stage that certain foliar herbicides can be applied.

On average a plant can produce 1,300- 4,000 seeds and large, hearty plants have yielded up to 26,000 seeds! (Howarth and Williams 1968). These seeds are highly viable and can remain so up to 39 years although the percentage of viability drops after 6 years. Champness and Morris (1948) found one million seeds per 2.5 acres in ag fields and up to 4.2 million seeds per 2.5 acres in grasslands.

Control Options

Control must be done immediately as these plants can spread quite rapidly. Grazing is not very effective. Horses, sheep, and goats will eat oxeye daisy and the viability of the seed is reduced when passing through the animal, but it is not killed. Cows and pigs generally avoid oxeye daisies. If a milk cow does eat it their milk has an off flavor to it.

Mowing does not successfully kill oxeye daisies. Like Queen Anne’s lace, it will prevent the mowed bloom from setting seed, but the plant will survive and bloom again only at a height short enough the mower blades have no effect.

Prescribed burns aren’t effective either. The disturbance and open spaces resulting from burns make this management tool ineffective and could lead to further infestation.

Daisies are resistant to many herbicides but I have had good luck with Garlon® mixed with bark oil on first year plants in the rosette stage. Once in bloom, hand pulling is the best control with the caveat that one has to get all the seedlings around it and not miss one of those stems that has curved out and away from the initial group. Fortunately, they are easy enough to identify since they have an interesting purple striped pattern.


Oxeye Daisy, Leucanthemum vulgare

Another view of the incredible root creating system of Oxeye daisy.






Control Options

Control must be done immediately as these plants can spread quite rapidly. Grazing is not very effective. Horses, sheep, and goats will eat oxeye daisy and the viability of the seed is reduced when passing through the animal, but it is not killed. Cows and pigs generally avoid oxeye daisies. If a milk cow does eat it their milk has an off flavor to it.

Mowing does not successfully kill oxeye daisies. Like Queen Anne’s lace, it will prevent the mowed bloom from setting seed, but the plant will survive and bloom again only at a height short enough the mower blades have no effect.

Prescribed burns aren’t effective either. The disturbance and open spaces resulting from burns make this management tool ineffective and could lead to further infestation.

Daisies are resistant to many herbicides but I have had good luck with Opensight® on first year plants in the rosette stage. Once in bloom, hand pulling is the best control with the caveat that one has to get all the seedlings around it and not miss one of those stems that has curved out and away from the initial group. Fortunately, they are easy enough to identify since they have an interesting purple striped pattern.


Prescribed burns aren't effective either. The disturbance and open spaces resulting from burns make this management tool ineffective and could lead to further infestation.






























































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































Another view of the number of seedlings “hiding” after pulling the main plant. Be sure to get them all!


If I find hand pulling results in too much soil disturbance, another technique I’ve used successfully with the large clumps is to cut them low to the ground and spritz with triclopyr (Garlon 4®) in bark oil. I use this same technique with Hypericum perfolatum, Common St. John’s wort.

One last word of caution – if you’re buying pre-mixed, pre-packaged seed Oxeye daisy could well be in the mix. Be sure you know each species in the mix and source your seeds from a company specializing in native plant restoration.


Champness, S.S. and K. Morris. 1948. The population of buried viable seeds in relation to contrasting pasture and soil types. Journal of Ecology 36: 149-173.

Howarth, S.E. and J.T. Williams. 1968. Biological flora of the British Isles. Journal of Ecology 56: 585-595.

Washington State Noxious Weed Control Board. 2000. Written findings of Leucanthemum vulgare. Accessed 04 June 2016

Mouse-eared Chickweed (Cerastium vulgatum)

This agricultural weed is originally from Eurasia. It is found across most of the United States on abandoned cultivated lands and, in our case, a prairie restoration in a once-cultivated field. It won’t tolerate plowing, but the seed must remain viable for several years.

The meaning of the species name is “common or generally accessible;” I prefer to take it more literally and call it “vulgar” as in offensive or indecent! The name “chickweed” comes from plants used as starter feed for chicks.

This particular chickweed gets its common name from the cute little fuzzy leaves that resemble mouse ears. But when it’s on your land, there isn’t anything cute about it. It spreads by seeds and rootlets which are set down from the spreading arms of this mat-forming plant. C. vulgatum blooms from spring to fall as long as it’s cool and moist. This sun-loving plant will form a green mat is very little time and will shade out germinating prairie plant seeds. I have not been in the right place at the right time to know when one first comes up to time how many days before it covers a certain area. We’ve had a fairly warm, early spring this year (2016) with maybe 15 days of greening up. With that said, the picture below shows how quickly this chickweed can spread.


Cerastium fontanum, mouse-eared chickweed

Because this plant grows by hugging the ground and spreading out, the best control is by herbicides. Mowing close cuts the first blooms off but further mowing encourages its low creeping habit. A 2% mixture of glyphosate is sufficient to kill the plant. It’s important to do this when it first pops up from the ground. Its blanketing effect is sufficiently quick that herbiciding it at this stage creates “deserts” – areas of barren ground. When this happens, you can overseed or plant seedlings in the area.