The word arboretum refers to a collection or park of tree species. In the 1800s and early 1900s, all self-respecting manor house owners had their own arboretums. Niskala arboretum was the show park for Jakob Kavaleff, who was particularly fond of conifers and their special shapes. He imported seeds and saplings from abroad and experimented with them in his nursery and arboretum. The first trees were planted in 1905. Ownership of the arboretum transferred to the City of Helsinki in 1961.
The arboretum has had its ups and downs over the years. At times it was neglected almost entirely, and the park soon became overgrown. The first thinnings were made in 1971 and 1972 to save individual trees of high value. The park was granted protection status in 1984 on the basis of its valuable trees, shrubs and herbaceous vegetation. The area is also important for its birdlife and bats.
A comprehensive plant inventory was completed in 2004. The inventory identified 70 taxa (species, subspecies and varieties), including 53 taxa of shrubs. The latest maintenance and usage plan is from 2006 and covers the protected nature reserve area and extension of the arboretum. The planting of new saplings began in spring 2009.
The aim is for the arboretum to develop into a natural, well-maintained and diverse woodland garden in which a wide assortment of Finnish and foreign tree and shrub varieties grow. Accordingly, the park’s shrubs and perennials have been diversified while maintaining the natural plant life. The multilayered woodland landscape has been preserved and complemented by pretty vistas opening up along the path through the arboretum.
Popular features of the arboretum include its vibrant colours in spring and autumn, the variation between open and closed spaces, and the emphasis on beautiful details. The natural values have been safeguarded, for example by preserving the decaying and rotten wood from different tree species in all its forms. The thick shrubs, multilayered forest, meadows, wet hollows and pond provide a habitat for diverse species.
When planting new saplings, mainly conifers have been selected for the western part and deciduous trees for the eastern part. Individual and impressive taxa are represented in a few individual plantings and in only specific sections. The park is divided into geographical sections for Europe, Finland, East Asia, Japan, North America and section for conifers. The focus is on species that were popular in Finland during Kavaleff’s time in the early 1900s. The trees represent pure species and cultivated or specially selected varieties.
In 2012, the plant register for Niskala arboretum listed over 500 taxa. The City of Helsinki hopes that the arboretum will develop into a leading centre for dendrology in Finland amidst the attractive countryside just half-an-hour’s bus ride from the city centre.
Arboretum’s signposting (pdf) Niskala Arboretum