Picea

Serbian spruce grows naturally only in a very small area on the borders of Bosnia, Serbia and Montenegro, at altitudes between 1000-1500m above sea level. It is an interesting relict species from pre-glacial times, when it had a much wider range in Europe. It can be recognised from a distance by its shape, which is very narrow. Another way of recognising it is the colour of the needles, whose lower surface is shiny silvery, easily visible when the ends of the branches turn gracefully upwards.

Nowadays this species is quite common in gardens and other landscape plantings in southern Finland. It resists pollution well, which favours its use in towns and along roadsides. It is at its best, however, in groups or small picturesque woods where these tall trees present almost a Gothic cathedral-like appearance. In suitable places it can be planted as a productive landscape species, and in recent years has become increasingly popular as a Christmas tree.

The oldest Serbian spruce plantation at Mustila was planted in 1914 using seed received direct from Bosnia in 1907. The growth rate bears comparison with local spruce, and it is much longer-living than many other exotic spruce species. The best plantation is along the footpath just west of Kenkäkallio, or Shoe Rock, but it also grows on the western side of Alppiruusulaakso, or Rhododendron Valley, at the edge of Tammimetsä, or Oak Forest and on the western edge of the Arboretum, at Nokkala.

A. F. Tigerstedt mentions the Meyer spruce (P. meyeri) in his book “Havupuut” (Conifers), published in 1921. He listed the various Chinese spruce species still missing from the Mustila collection and ended: “which may gradually, one by one, be obtained [for Mustila]”. In some cases, obtaining these species has taken longer than he might have expected: Meyer’s spruce was finally planted in the Arboretum in 1991.

Native to the northern provinces of China, Meyer spruce closely resembles the Chinese spruce (P. asperata), including the grey-blue needles. Meyer spruce does not suffer the same fungal infections as the North American blue (also called Colorado) spruce (P. pungens), so it has rapidly become popular as a landscape tree especially in those areas of the U.S.A which have wet summers. In Finland it has hardly been grown at all. At Mustila, Meyer spruce can be found at the southern edge of Alppiruusulaakso (Rhododendron Valley), where they have grown extremely slowly in dry poor soil but have suffered no winter damage at all.

Black spruce grows in North America in a broad belt from Alaska to Newfoundland, and as far south as the Great Lakes. In the southern parts of its range it grows mainly on mires, further north also on drier soils. This is a small slim tree with a narrow cylindrical crown. Needle colour varies: dark green, blue-green, or grey-green. The cones are small and ball-shaped, often growing in tight bunches near the crown, and remaining on the tree for several years. Black spruce can regenerate throughout most of its range by layering from branches in contact with the ground.

Black spruce grows successfully in Finland, but is a short-lived species. At Mustila, all the old plantings have died from insect attack. New plantings have been made from the 1990s onwards, e.g. in the spruce collection area in the western part of the Arboretum. Using a variety of seed sources, it is possible to find trees which are suitable to local conditions and less susceptible to insect attack. West of the Arboretum, on land belonging to Mustila Manor, there is an old plantation of black spruce from New Hampshire seed which is still in good condition.

The contribution of black spruce to Finnish forestry is limited to its use in exceptional conditions, for example plantings on cold peat bogs. But it is a useful addition for landscape use, being hardy, dense, tough and moderate in size. It has also been used occasionally as a Christmas tree in recent years.