SPECIALIST HEMLOCK WATER DROPWORT CONTROL SERVICES

OUR SPECIALIST CONTROL SERVICES WILL TREAT OR ERADICATE THIS SPECIES. TO FIND OUT IF YOU HAVE HEMLOCK WATER DROPWORT USE OUR FREE ID TOOL OR BOOK A SURVEY

treatment & removal

Hemlock water dropwort can be treated with a suitable aquatic herbicide however mechanical excavation is the best method to completely remove the visible plant and any remaining roots systems, especially the long tap root. All parts of the plant need to be completely removed to ensure no fragments are left behind as these can flow downstream to form new plants.

Monitoring is advised as seed dispersal can create new clumps which will quickly become invasive.

Any contact with the plant during treatment or eradication must be done with suitable protective clothing (PPE).

To find out the best way to control or remove Hemlock water dropwort, and the best time of year to have treatment or eradication carried out get in touch.

WHY IS HEMLOCK WATER DROPWORT A PROBLEM?

britain’s most toxic plant

These root of this plant have an alternative name of ‘Dead Man’s Finger’s’ due to their appearance. No British wild plant has been responsible for more fatal accidents, in one instance a party of workmen repairing a hole that had appeared in a Canal tow-path dug up and ate the roots, mistaking them for parsnips. This proved fatal within just 3 hours for one of the men.

ABOUT HEMLOCK WATER DROPWORT

SCIENTIFIC NAME: Oenanthe crocata
ORIGIN: UK

Hemlock Water dropwort is a native plant found in shallow water, streams, ditches, rivers and lakes. It propagates via prolific seed production following flowering, the seeds are readily spread via waterways.

This is the most toxic plant to both humans and animals in Britain. Not to be confused with its equally toxic cousin Hemlock (Conium maculatum). In pre-Roman Sardinia Hemlock water dropwort was used as a humane agent of euthanasia. Ingesting the plant caused contortion of the face into a smile (named risus sardonicus by physicians), and so it became known as the plant that caused a ‘sardonic smile’.

• Perennial plant growing up to 150 cm tall.
• Hollow, cylindrical, grooved stems up to 3.5 cm across.
• Flat heads of small white flowers appear in late spring that can grow up to 1.5 m in height.
• Leaves look similar to the herb Chervil and smell of parsley, making it easy to mistake as a safe foraging plant.

HABITAT

Common in shallow fresh water streams, marshes, lakes, ponds, canals and wet woodland.

IMPACT: HIGH

Its tuberous root can become exposed when flooding, dredging or dry summers cause bank erosion. The tuberous roots are sweet tasting (apparently) and appear palatable to grazing animals. For amenity managers landowners/farmers with land used for grazing at certain times of year, it is of particular concern due to its high toxicity.

TOXICITY: HIGH

All parts of the plant are deadly poisonous but the roots contain the highest concentration of toxins. The toxic compound is oenanthotoxin, which poisons the central nervous system of mammals. The symptoms of poisoning include convulsions, seizures, nausea, diarrhoea and tachycardia. Quite small amounts can be lethal.