Invasive species

Identifying invasive species is important so that they can be effectively controlled and prevented from spreading to new areas. This website presents the characteristics of invasive species commonly found in Espoo, issues caused by them and means of controlling them. The content of this site is based on the City of Espoo invasive species policy.

Espoo residents and city employees can report their invasive species observations directly to the Public Works Department through the City of Espoo’s feedback system. Observations can also be reported through the national portal for invasive alien species.

The city mainly controls harmful invasive plant species in connection with normal maintenance work as well as construction and renovation projects. Some control activities are carried out by outsourced service providers. In line with the plans for the control of invasive species, the aim is to focus control efforts on areas that are particularly important due to their natural values. Mechanical cutting and uprooting are the main control activities.

The City of Espoo encourages residents and associations to organise and participate in a community effort to stop invasive species. With comprehensive cooperation, there is still time to stop the spread of invasive species and ensure that the nature around us will remain diverse, comfortable and safe for us all.

Read more about invasive animal and plant species in Espoo

Read more about invasive species

• Plant pests and diseases(external link, opens in a new window)
• Vieraslajit.fi(external link, opens in a new window) – The National alien species portal

The giant hogweed, with its red-spotted floral stem, can reach the height of 2–3 metres and has large cleavage leaves. The wide, white inflorescence of the giant hogweed bloom in June–August.

Means of controlling of the giant hogweed include cutting its flowers, reaping, uprooting, covering the growth and chemical treatment. Please note that protective clothing must be worn when controlling hogweed.

Additional information on Giant hogweed(external link, opens in a new window)

The Himalayan balsam is an annual, succulent plant growing 1–1.5 metres high, which spreads into vast vegetation in damp areas. Its pink flowers bloom in July–September, and it has narrow, serrated leaves.

Means of controlling the Himalayan balsam include weeding and reaping before blooming.

Additional information on Himalayan balsam(external link, opens in a new window)

All Asian knotweed species grow tall and have vertical bamboo-like stems that grow 2–3 metres high. They bloom in August–September with fairly inconspicuous white flowers.

Means of controlling the Asian knotweed include deep uprooting, continuous reaping of the terrestrial parts, covering the growth and chemical treatment.

Additional information on Japanese knotweed(external link, opens in a new window), and Giant knotweed (external link, opens in a new window)

The Japanese rose is a shrub that grows 0.5–1.5 metres tall with densely thorny branches and large, single-layered flowers that are usually intensely pink but sometimes also white.

Means of controlling the Japanise rose include uprooting the plant or shrivelling it. Picking the berries prevents birds from eating them and thus spreading the rose to new areas.

Additional information on Japanese rose(external link, opens in a new window)

The Garden lupin is a leguminous plant growing 1–1.5 metres high, which blooms in June–July with a tall, cluster-like flower that can be blue, purple, pink or white.

Lupin seeds retain their germination capacity in the soil for a long time. Individual lupins or small-scale lupin growths can be uprooted. Larger areas of lupin can also be destroyed by reaping them several times during the summer.

Additional information on Garden lupin(external link, opens in a new window)

The yellow skunk cabbage is a large, wetland species belonging to the arum family. By midsummer, it grows a metre-wide rosette that covers all native wetland vegetation.

However, seedlings and young rosettes found early enough are easy to uproot.  The flowers should be cut off by the end of May at the latest before the seeds mature. Seeds of the yellow skunk cabbage may retain their germination capacity for several years.

Additional information on Yellow skunk cabbage(external link, opens in a new window)

The American mink is a small weasel-like animal with a body that is 35–45 centimetres in length. The American mink is dark brown or blackish-brown in colour and has a white spot under its chin.

A hunting licence is not required for catching a mink, but you must have the landowner’s permission. However, catching any animal is only allowed if you are familiar with the requirements of the law and are able to act accordingly. A common method for controlling the mink is trapping.

Additional information on American mink(external link, opens in a new window)

The Spanish slug grows 7–14 centimetres long and is typically of dirty, rusty brown colour.

An effective way of controlling the Spanish slug is to collect them in buckets in the spring before they lay their eggs. The slugs can be terminated painlessly by immersing them in boiling water.

Additional information on Spanish slug(external link, opens in a new window)

The European rabbit is a 34–50 centimetre long rabbit. Compared to the blue hare and the brown hare, the European rabbit is smaller in size and has shorter legs and ears. The European rabbit is typically of brownish-grey colour.

To catch a European rabbit, classified as small game, you need a hunting licence and a hunting permit issued by the landowner. Trapping and netting are effective methods of controlling the European rabbit, but ferrets can also be used to hunt them. The City of Espoo controls the European rabbit populations by ordering their catching as an outsourced service.

Additional information on European rabbit(external link, opens in a new window)

The brown rat is an omnivorous rodent that can grow up to 11–29 centimetres long. The rat’s fur is of brownish-grey colour, and the abdomen is lighter than the rest of the body.

The most efficient way of controlling the brown rat population and protecting your property is to ensure that all waste is kept in closed containers and that leftover food is not composted in an open compost. Rats can also be controlled with the help of contractors using bait boxes.

Additional information on Brown rat(external link, opens in a new window)

The raccoon dog is a small predator that is slightly smaller than a fox and grows to be 45–70 centimetres in length. It has short limbs, small rounded ears and a masked colouration on its face. The main colours of raccoon dog fur are mottled black and grey or yellowish-brown.

A hunting licence is not required for catching a raccoon dog, but you must have the landowner’s permission. However, catching any animal is only allowed if you are familiar with the requirements of the law and are able to act accordingly. The most typical forms of raccoon dog hunting have been trap and carcass hunting as well as dog hunting from nests.

Additional information on Raccoon dog(external link, opens in a new window)

Many invasive plant species have spread to vast areas in Espoo, and it is important that we fight them through community effort. More information on invasive species and how to control them is available on both the City of Espoo invasive species website and the national invasive species portal.   

1. Once you have found a suitable location with invasive species, ask the landowner for permission to control them.

2. . If the community effort is to be held on city grounds,  fill in the registration form(external link, opens in a new window).

3. Assemble your team or contact, for example, the local residents’ associations, which may organise community efforts in their respective areas. You can also weed out invasive species with a smaller group or by yourself while having a walk, for example.

4. After you have filled in the registration form, you can pick up garbage bags at the place you selected in the form. On the day of the community effort, weed out the invasive species and pack them in garbage bags. 

5. Place the garbage bags containing invasive species in a place where city employees can easily pick them up in a vehicle. We only collect garbage bags containing invasive species from land managed by the city. The number of garbage bags and street address will be notified in the registration form.

The best results are achieved when invasive species are eradicated early in the summer before they bloom.