Giant Hogweed is a large invasive plant found in Britain, northern USA and European territories like Germany, France and Belgium. As it is named, its appearance is also very giant, have dark reddish-purple stem which can grow up to 5 meters tall and large leaves which can expand 1.5 meters across and 3 meters long. It produces umbrella shaped flowers, each of which can produce up to 50,000 seeds. Giant Hogweed was introduced in UK in 19th century which have now widespread along the river banks and waste lands. It is often found along paths, waterways, railway lines and can grow on land disturbed by humans.
Giant Hogweed is invasive in nature, can cause severe damage to native species and it is hazardous for human beings. To plant or grow giant hogweed is a legal offence and a person will be guilty to pay a fine of £5,000 or up to 2 years imprisonment, as stated in Section 14(2) of the Wildlife and Countryside Act 1981.
Understand why is Giant Hogweed so hazardous? : Giant Hogweed is phototoxic plant, which means on cutting the plant or brushing against the plant it releases a sap which is a sensitive chemical to sun exposure. If a human skin gets in contact to sap and expose to sun light or ultra violet rays, it can cause severe skin inflammations and blistering. Initially the skin color turns red and starts itching. Within two days the blisters turns in to burns, even hospitalization may be necessary. This burn forms scars which can last for years. If its sap is came in contact with eyes it can lead to blindness. This phototoxic chemical is present in its leaves, roots, flowers, seeds and stem.
Giant Hogweed does cause damage to other native species of plants, as it has large leaves which does not allow sunlight to reach to other plants and even its strong deep roots takes all the nutrients which leads to stop growth of other plants. It is very important to identify this invasive weed and eradicate.
How to control or eradicate Giant Hogweed? : Giant Hogweed grows repeatedly and produces several thousand seeds. Even if one plant dies there are thousands of seeds under soil waiting to take their place.
There are some manual techniques for Giant Hogweed control and treatment, one of which is to cut them off repeatedly. This will not allow plant to produce more seeds and will gradually die.
Other way is to remove the plant from its taproot, this is required to be done very carefully with precautions and protected clothing.
It is been noticed that the chemical contains are not affected on goats and sheep, so grazing can also be an alternative to control the growth of Giant Hogweed.
If the population of giant hogweed is very dense then invasive species expert ecological consultants are required to carry the Giant hogweed treatment and control. Ecological consultants can use herbicides specific for killing large weeds and are effective in eradicating Giant Hogweeds.
If the seeds have already took place underground, the repeated giant hogweed treatment is required to control its spread.
Brenda Rosenthal, an expert ecological consultant and invasive species have years of experience in giant Hogweed control and treatments.