The dangerous hogweed is only just beginning its growing season, with its lush leaves still spreading close to the ground. However, if you spot hogweed in your yard, it should be dug up as soon as possible.

"Most people probably don't encounter hogweed very often anymore because we've largely eliminated it from common public areas, such as roadsides and the spaces between populated areas. It's moved into more remote corners and forest edges," said Eike Tammekänd, an invasive species control expert at the Environmental Board.

Hogweed grows throughout Estonia. It is least common in Hiiumaa and remains most widespread in Harju County. The biggest concern is in Tallinn, where the plant has been introduced into the urban environment in large quantities through landscaping soil.

"Its spread appears to show signs of expanding, but at the same time the number of plants at known sites is declining and little by little there are also sites where the plants have been completely eradicated. Control work can be carried out throughout the summer. Once the seeds have turned brown, we don't recommend entering an infestation because the seeds can stick to clothing and be spread elsewhere," Tammekänd said.

The spread of hogweed has declined over the past decade. Eradicating the plant requires many years of continuous control efforts, but sustained work can successfully eliminate it. This year, the Environmental Board plans to carry out control work on more than 2,500 hectares across thousands of infestation sites.

"Hogweed produces a huge number of seeds and those seeds can remain in the soil for years without losing their ability to germinate. If the seeds have already ripened, the situation becomes much more difficult and it's best to burn the dried seeds. But if it's still in its vegetative stage and looks like a giant cabbage, it can simply be composted," said botanist Toomas Kukk.

Hogweed is an enormous plant whose leaves can grow to cover an area of up to one square meter. Its vigorous growth depletes soil nutrients, making it much more difficult for native plants to become established in the same area.

Hogweed is dangerous because its sap contains toxic chemicals called furanocoumarins. When this sap comes into contact with skin and is exposed to sunlight, it causes a severe, burn-like condition called phytophotodermatitis.

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