Finnish housing association spends thousands to remove invasive plant now spreading from neighbouring city land

A housing association in Järvenpää spent thousands of euros removing giant hogweed (Heracleum mantegazzianum) from its property, only to see the invasive plant thrive on adjacent land owned by the city, reports Finnish public broadcaster Yle.

The association’s chair, Markku Niemelä, told Yle that despite hiring contractors to excavate 70 metres of overgrown hedge and 40 square metres of garden beds—followed by truckloads of replacement gravel and soil—the plant continues to regrow. “It’s still spreading from nearby areas, both by seed and root,” he said.

Finland’s Alien Species Act, amended in August 2025, bans the cultivation, sale, and spread of giant hogweed, classifying it as nationally harmful. Property owners are legally required to remove it, but enforcement remains inconsistent. Niemelä noted that neither neighbouring associations nor the city have cleared their land, despite his reports to municipal authorities going unanswered.

Järvenpää’s area inspector Ritva Lindroos acknowledged the city has struggled to keep pace. While some invasive species like garden lupines and Himalayan balsam are managed through contractor bids and volunteer efforts, giant hogweed was only added to the removal list last autumn. “We’ve cut it down, but the work is ongoing,” she said.

Reima Leinonen, Finland’s invasive species coordinator, confirmed that although violations can theoretically face penalties—including fines or compulsory removal—resources for enforcement are limited. “Our priority isn’t issuing fines for every plot,” he admitted. Yet he insisted compliance remains critical: “If we don’t act, our nature will be unrecognisable in time. The law is clear: owners must remove harmful invasives from their land.”

Experts urge reporting sightings via the [vieraslajit.fi](https://vieraslajit.fi) portal, though the Finnish Safety and Chemicals Agency (Tukes) can only respond to a fraction of cases.