control houndstongue

Houndstongue goes by a myriad of names. Some call it sheep bur, others sheep lice, while others call it woolmart. Whatever the name, be it beggar’s lice or dog’s tongue or glovewort, the naming refers to a noxious plant that has been a headache to many farmers. In this article we will talk about how to control houndstongue in your yard.

The presence of this plant in a field will adversely affect the health of livestock. How you ask? Well, the leaves of this plant are poisonous and can lead to the death of animals when consumed. Houndstongue is a weed and one that spreads at fast rates. As it grows, it affects the ecological system such that it creates unconducive conditions for native plants.

Fun Fact

Other than being a source of medicine, houndstongue was also useful for magical potions. It goes that wearing a leaf of this plant in the shoe was a sure way of protecting oneself from dogs. Thus, the name houndstongue.

Houndstongue description

Houndstongue’s scientific name is Cynoglossum Officinale L. It is native to Europe and Asia. As is the case with most weeds, it found its way to North America by accident. In this case, it was in the form of contaminated seeds, with the first sighting of the weed having taken place towards the start of the twentieth century. That was in Oregon, and Montana before the weed became a national problem, having affected numerous counties.

This plant does well in disturbed areas such as roadsides, trails, formerly used croplands, and areas where logging takes place. It also thrives in rangelands, riparian areas, wooded areas, and pastures. It can do well in shaded areas and will grow in most soil types, including clay sub-soils. Denying it access to sunlight will not stop its growth.

Given its ability to do exceptionally well in varied conditions, containing it has been a problem.

Houndstongue US

Reports of houndstongue in the US

Uses of houndstongue

For a long time, people relied on houndstongue as a medicinal herb. However, you will hardly find people using it in this modern age.

Its foliage contains allantoin, which aids in healing the body. People using this herb should exercise caution as high levels of this agent can lead to cancer. Interestingly, the same agent has been used to treat cancer complications, as well as insomnia.

You can use different parts of the plant to make remedies. Take the roots as an example. They have proven to be effective in treating diarrhea, colds, coughs, and other minor ailments. The leaves are useful in relieving pain and digestive problems. Other than internal use, people can also use the plant parts on their skin to deal with bites, wounds, and minor injuries.

But even with all these benefits, there is no denying that this plant has become a menace. Hence comes the need to get to the root of the problem. And it all starts with the identification of the houndstongue.

How to Identify houndstongue

Houndstongue belongs to the Borage family, and it thus exhibits features that are characteristic of this grouping. It has long leaves with white hair and prominent veins covering both the surfaces. Some people have likened these leaves to a dog’s tongue- slender and slightly droopy. Does this remind you of a pet somewhere? The leaves alternate and will measure about four to twelve inches in length on the lower side with leaf stalks. Leaves on the upper side lack petioles and appear to be similar.

houndstongue flower buds

Houndstongue flower buds

A woody taproot supports this plant. Its stem is hairy, and it stands tall, branching out towards the ends. It feels heavy and grows to heights of about 1.5-3 feet.

This plant grows quite fast. In its second year, you should expect a flowering stalk with a height of at least eight inches. Where the growing conditions are ideal, the stalk can be as tall as thirty inches. It produces flowers with varying colors- anywhere from red to burgundy.

Fruits produced have a flat shape with barbs on the side and a hard husk. These barbs stick on fur and fleece, as well as clothing. Where this weed is in pastureland, cattle and other animals contribute to its spread. Seeds remain viable for up to three years.

houndstongue flowers

Houndstongue flowers

Growth Process

The houndstongue is biennial, and it survives by the reproduction of seeds. The seedlings start towards the end of spring and the start of summer, from which grows a thick taproot. The root system develops fast and can be as long as three feet within one year.

It stores the nutrients needed for the production of seeds. Where the weather is favorable, a flowering stalk develops in the second year. Where the weather is unsuitable for the growth of the stalk, the process can take place in the next year.

Flowering takes place between May and July, and this gives rise to seeds that mature by August. At least 300 seeds come from a single plant each year, and in some cases, they can be as many as 2000. Once the seeds are mature, they can fall on the ground or remain on the plant.

Seeds on the ground can germinate if they are at least an inch under the soil. Otherwise, they would dry out. Those on the plant get dispersed by animals and humans.

Cynoglossum officinale after growing season

Cynoglossum officinale after growing season

Why is houndstongue invasive?

At this point, we have touched on some of the adverse effects of this weed. How about we delve deeper into this?

When seeds attach themselves to the wool or hair of livestock, they create problems for the farmer. Not only would the farmer need to take time in removing the seeds, but this process would also cost money. Thus, the returns from the venture would be less. And if a farmer decides to market the fur without removing the barbs, the value fetched would not be encouraging.

But that’s not the worst part. These seeds can also get to the eyelashes of animals and have been known to cause damage to eyes. That would be quite a loss to the farmer. But one that is not as bad as losing the whole animal altogether. In some cases, farmers have lost their animals to poisoning after their animals consumed houndstongue.

The good thing is that houndstongue is not the first choice for most animals. In most cases, they would avoid it and seek other plants. But during harvesting, one could make a mistake and bundle up this weed with other plants. Upon drying houndstongue, it would be palatable to animals, and they could thus consume lots of it.

Also, where animals do not have much variety from which to choose, they would go for what is available. And where the choice is houndstongue, they would take it. It gets worse where herbicides are in play as they have been proven to increase the palatability of this plant.

How to tell if your livestock is poisoned?

In small quantities, this weed would not affect animals much. But where they have consumed it in large quantities, it can become a problem. You can tell that your animals are not well if: they are constipated or have diarrhea, kick at their bellies, appear nervous, lose interest in food, prefer to be still, lower their heads and are sensitive to light. Where one or more of these signs are apparent, it might be time to call in the vet and get the animal out of the pastureland.

Did you know that houndstongue is a silent killer? An animal could consume lethal amounts of this weed and survive for six months or more before they die. Thus, you may be thinking that all is well, only to wake up one day and find that your livestock is dropping dead one after the other. Cattle and horses are the most susceptible to poisoning, with sheep showing higher levels of resistance.

It’s better to avoid the chance of poisoning altogether. You can do so by ensuring that the pasturelands are free of this weed. When harvesting hay for your animals, ensure that you do not mix the crops with houndstongue.

How to control houndstongue

If you can prevent the spread of houndstongue, you will have an easier time containing it. But if you let it spread, you will have a lot of work cut out for you. And the effects of its spread will cost you more than what you would use in preventing its growth.


How can you prevent houndstongue from spreading? Well, it is pretty straightforward. For one, you have to ensure that the spread of seeds is minimal. Sure, you cannot prevent the actions of the wind or keep seeds from falling to the ground. But you can contain your movements and those of your livestock to prevent further dispersal.

Containing Infested Areas

Where you have infestations in your pastureland, you should contain them. That means that no humans or animals should access that area unless it is in a bid to get rid of the weeds.


Monitoring is essential as it helps you know when the weeds have sprouted. Make it a routine to observe the plants in the pasturelands and keep track of any new growths. Once you detect the spread of weeds, eradicate them with immediate effect.

Introducing Native Plants

Houndstongue, though strong, also has competitors. Get desirable native plants that can compete with the weeds and plant them in infested areas. That way, the weeds will have a hard time establishing themselves and will not increase in number. Where weeds have adequate access to nutrients and water, they grow at faster rates as compared to where they are in undesirable conditions.

In addition to prevention, you need to control existent infestations. The method of choice will depend on the extent of the infestation. Where the weeds are few, you can rely on techniques such as hand pulling and spot treatments.

Where the weeds have spread over a large area, you can use a combination of methods such as the addition of competitive native species and widespread application of herbicides. Also, consider the use of the land, the presence of other crops, and the cost and effectiveness of the methods. Here are some of the techniques which have proven to control houndstongue:

Mechanical control

Hand Removal

This technique works best for small infestations, where the root system is not extensive. In the first year, it is possible to get the whole plant out, with the root intact. It ensures that no fragments remain in the soil, and you can dispose of the plant in the prescribed manner.

You can burn the plants or put them in plastic bins, which you can take to a landfill. Using this method for large populations would not work as you may be unable to get the entire root crown. And with this in the ground, subsequent growths will occur.

physical invasive plant removal

Physical invasive plant removal is labor-intensive


Houndstongue does best in uncultivated land. That is why you will find it in rangelands and pasturelands. Tilling your land may thus be a way to keep houndstongue at bay. Do this continuously through the growing season, ensuring that you do so at several inches into the soil. This practice will damage any roots below the ground surface and keep the weeds from sprouting.

You can integrate this with the introduction of competitive plant species. If you plant the species towards the end of the fall or start of winter, they will be sturdy enough to compete for nutrients with the weeds. When choosing what species to introduce, look at its competitiveness, and how easily it establishes. It also helps to look at how well it would adapt to the soil conditions and the climate.


Defoliation through mowing, cutting and other means, has been used in the past. Some people have registered positive results with this method. However, they are short-lived. Cutting the plant above the soil surface will limit the growth of these weeds to some extent. However, the extensive taproot system will still be in place, providing the nutrients needed to support the growth of houndstongue.

As a result, when the mowing/ cutting stops, normal flowering processes will resume. And soon, seed dispersal will begin. This method is more of a band-aid as it does not get to the source of the problem. However, when you are assessing what options would work for you, defoliation might be a good start to control houndstongue.


Burning has also been used to control houndstongue. This practice takes place towards the end of summer, with an intent to destroy mature seeds. In this way, their dispersal can stop. Now, this is a double-edged sword. On the one hand, the seeds on the plant would get destroyed as a result of the high temperatures. But that is not always the case.

You will find that more often than not, the seeds on or in the soil do not get adversely affected by the heat. Instead, it stimulates their growth by proving them with the required conditions. Seeds can sprout as a result of the fire. Plus, the lighting of fires creates disturbances, which also encourages the growth of houndstongue. As is the case with mowing, this would serve as a band-aid.

Biological Control

Introducing a biological agent to control houndstongue would be both bad and good. On the upside, it would be the end of this noxious weed. On the downside, the agent would affect other plant species in this family. An excellent example of such an agent would be Mogulones crucifer, which feeds on roots. As much as it has led to the reduction of houndstongue species, it has also negatively affected rare native plants.

Research is ongoing in the hope of finding a better agent. As at now, none exists. However, there are other ways in which you can deal with this weed:

Chemical control

Herbicide application is the most extreme method to control houndstongue and the most effective. Where you are dealing with a large infestation, be it on rangeland, in the wild, or on pasturelands, this method would help. The good news is that many herbicides can help you control the growth of this weed.

The amount of herbicide you use will depend on the guidelines given by the manufacturer. The same goes for the application times. In most cases, you will find that the application should take place in spring, rather than in the fall.

Given that houndstongue is biennial, the application should focus on plants in the bolting and rosette stages. Those which have flowered will die towards the end of the season, and using chemicals on them would have little effect on their fate. This tidbit will save you tons of money and energy.

Several herbicides including 2,4-D, metsulfuron, and chlorsulfuron work well to control houndstongue.

Subsequent applications of the herbicide of choice will be necessary to ensure that seeds remain unviable. Note that the use of herbicides can increase the palatability of the weeds. Thus, after application, give the pasturelands a break to ensure that your plants do not get poisoned.


Houndstongue has, for long, been a source of remedies, both magical and medicinal. It has been used in the making of pesticides to repel rodents in gardens and storage rooms. However, even with all these upsides, this plant has proven to be a noxious weed. Hence, the need to control houndstongue.