Invasive species are plants that have been taken here by humans - but then spread in the wild and knock out native plants.

Parksliden is one of them. And one of the worst. It can grow to three meters high and quickly form populations that spread through long roots and push away other vegetation.

Hard to stop

And it is almost impossible to get rid of. If it is excavated, the soil must be treated as hazardous waste; it is enough that a rubbing root thread is dropped on the ground for the park slide to come back.

Skane is the worst affected. Many more observations have been made here than in other parts of the country.

Skåne peaks in Sweden when it comes to the number of observations of park slide. Photo: SVT Grafik

In Helsingborg, there are park slides in an unknown number of gardens but also in many places in the wild and in parks. For five years, conservationists have been combating the plant at a cost of between half and a million a year, without fail to remove it.

In the video above: See conservationists Nina Syde and Linda Hellberg tell about the fight against park slide.