Cole Anderson

Giant Hogweed Spreads!

There have been reported sightings of giant hogweed in residential areas. Hogweed is an invasive species of plant that can cause major harm to those who come in contact with it. If you get some of it’s clear liquid on your skin, it will cause a chemical reaction when exposed to UV light and cause your skin to blister and burn. The central fisheries board have also said that not only is this giant hogweed a threat to human health, but it is also a concern to streams and rivers.

This giant hogweed thrives along rivers and streams. Giant hogweed has a big canopy that blocks light from surrounding plants thus killing off the plants that hold the riverbanks together. Without these plants the banks of streams and rivers could erode away. The reason why giant hogweed spreads so quickly and in vast numbers is because when it comes time to produce seeds, all of the seeds from the plant just fall into the river or stream and are carried down great distances until they are washed ashore and more giant hogweed grows. Giant hogweed plants produce about 5000 seeds per plant so you can imagine the amount of hogweed plants are produced each year. Winter floods will brake apart the weak riverbanks and wash dirt into rivers and it has been shown (Gargan & Caffrey, 1991; Caf- frey, 1992) (E.I.F.A.C., 1974; Reiser & White, 1988) that this dirt will affect the spawning of fish in the area. This dirt build up in slow flowing parts of the river will create a perfect habitat for water plants to grow (Caffrey, 1990) and could potentially slow down the river or stream and may even block it completely, destroying many animal’s habitats.

Even though there is a lot of hogweed found along rivers and streams, there is also an abundance of hogweed along roadsides. This could pose a danger for people because you don’t feel pain when you first come into contact with hogweed, you just get a clear liquid on you and within ten minutes the chemical reaction will occur with the UV light and cause blistering. The fluid from hogweed can cause temporary and even permanent blindness if you get this fluid in your eyes. Small children are in danger because this plant is about as tall as a child and if, for example, they are playing in vacant lot, a stream, or a river, even under parental supervision they can come into contact with giant hogweed and get this clear liquid on them.

Scientists are studying giant hogweed very closely and trying to figure out how to stop it from spreading and eventually get rid of the invasive plant. They have decided to try and cut the plant down to the ground at different times of the year. Tiley & Philp found that when the giant hogweed is cut down in the end of June, they produce less seeds and therefore less new giant hogweed plants are produced. Other methods of controlling this giant invasive species have been tried, but are very expensive compared to just cutting down the giant hogweed. These other methods include various types of pesticides but the problem with these pesticides do not just kill the giant hogweed, the surrounding native plants are also killed. You can target big clusters of giant hogweed, but you can not get rid of all of it without killing other plants with these methods.

Authorities are asking residents to purchase a hogweed removal tool to cut down some of the giant hogweed in their local area. This tool is a blade on the end of a long pole so that the user can cut down the giant hogweed without getting any of the dangerous liquid on them. With the help of the community and the research done by these scientists we can eradicate this invasive giant hogweed.

References:

Hydrobiologia 415: 223–228, 1999. J. M. Caffrey, P. R. F. Barrett, M. T. Ferreira, I.S. Moreira, K. J. Murphy & P. M. Wade (eds), Biology, Ecology and Management of Aquatic Plants. © 1999 Kluwer Academic Publishers. Printed in the Netherlands.