Prunus

One essential feature of Japanese gardens is the flowering cherry tree. But the characteristic ornamental cherries used in Japanese gardens are not hardy in Finland, so alternatives are more than welcome. The Kurile cherry is one of the smallest and hardiest. It flowers in early May with faintly pink, almost white blossoms. Another colour show occurs in autumn when the leaves take on brilliant orange shades.

The species was originally brought to Europe from northern Japan, and it continues to be imported for nursery sales and landscaping. The plants at Mustila are from a different source: they were purchased as seed at the turn of the century from the Russian Far East, probably collected on Sakhalin or Kunashir Island. They come into leaf and also bloom slightly earlier than trees of nursery origin.‍

Unfortunately this East Asian species is little grown in Finland. Although its flowering can’t match the decorative Japanese cherries, which blossom on bare branches, its habit and hardiness make it an excellent addition to the selection of flowering trees available. The white flowers appear after the leaves. It grows into a beautiful small tree, sometimes multi-stemmed, with the branches placed in attractive layers. The positioning of the leaves indicates a degree of shade tolerance greater than in most cherries.

The unusual clusters of flowers form on short thorn-like fruit spurs, which are not a normal feature of the Prunus genus. The flower bracts persist even when the black bitter fruit have ripened. The leaves are oblong with toothed edges. Their autumn colour varies according to origin and growing conditions, from yellow-brown to a handsome pale or rust-red.

The Mahaleb cherry is native to Europe and the Near-East. It has long been in cultivation all over the world and much used in grafting, for example as root stock for the sour cherry, Prunus cerasus. Particularly in North America, it is used as hedging and its seeds have been spread into the wild by birds, which has also happened on the island of Stora Karlsö, in Sweden’s Gothland. The fruit is also used industrially, the skins smelling aromatically of coumarin.

The tree blossoms at the same time as the leaves open, in clusters of as many as ten white scented flowers on the previous season’s growth. Although the flowers are small there are so many of them, and the leaves so small, that they cover the tree like a white veil. Flowering is probably best when the tree grows in poorish soil in full light.

The cherry itself is somewhat bitter in taste, ripening to black in autumn. It is small, with little flesh around the stone seed, but the spicy aroma is rather special and pleasant. The small pointed leaves stay long on the tree, until the first hard frosts. The specimens at Mustila are of Russian origin, planted in 1996, and have shown excellent winter hardiness.