Prunus

Virginian bird cherry from North America is a tall shrub or shrub-like tree, growing naturally from the Pacific coast all the way to the Atlantic. In Canada it is a popular garden shrub, with attractive features throughout the year, like the cherries. When the leaves first break they are reddish in colour, passing through dark slightly shiny green in summer to a beautiful yellow in autumn

Abundant white flowers appear soon after leaf break, about two weeks later than the native bird cherry (P. padus). The fruit, which ripen in late summer, are dark red to almost black, and edible. Mustila obtained a batch of seed in 1992 which had been collected for a fruit improvement project from the best specimens throughout Canada. Some of the resulting shrubs produced abundant flowers and fruits, but the taste was always typical of the species: sour, a trace of bitterness, even astringent. In America the berries are used mainly in jams, juices and pies, but the large, slightly poisonous seeds must be removed first.

In Canada there are selected varieties whose leaves are green on first breaking but gradually change to red or dark red, such as P. virginiana 'Shubert' (often wrongly written in the German way 'Schubert'). There are also forms which have been found among seed-produced plants whose foliage is a clear red when first opening. The black-berried P. virginiana subsp. melanocarpa is worth noting, and there is also a white-berried form.

This Far East species is something of a mystery, whose description isn’t easy to find in the literature. Nevertheless, it has long been known in its native range. It – and other similar plum species – has been grown from seeds by the Chinese and Koreans especially in the Ussuri and the Yalu River valley areas. It resembles the Japanese plum (P. salicina). The American have taken into cultivation a Japanese plum variety called ‘Mandshurica’, whose description is very close to P. ussuriensis.

According to the literature and information on its natural range, the species is extremely cold hardy. There are statements from the early 1900s claiming that it had survived several winters and even flowered on the extreme Irkutsk plateau and Transbaikal in Russia. More recently it has been used in hybridising to produce hardy plum varieties.

The specimens growing at Mustila haven’t really thrived. It may be that the species is too continental, and the local climate here, with its rapid weather changes in spring and autumn, doesn’t really suit it. However, elsewhere in Finland it has even produced fruit but all-in-all, experience so far is very limited.

The black cherry, native to North America, has a conical habit with shiny dark green, narrow oval leaves. In warm autumns it turns various shades of yellow and red. The species flowers after the appearance of the foliage, a week or two after the Finnish native bird cherry, P. padus. The fruit of the black cherry is larger than the bird cherry, at first red but ripening to almost black.

The best individuals have a very regular habit and eventually grow into large tree, larger than the native bird cherry. Gradually the branches start to droop, and branches and trunk take on an attractive rough texture. The wood itself is both beautiful and valuable, known as cherry wood.

In its native area, it is almost impossible to find in nurseries, perhaps because it is too ordinary there. So far it has been little grown in Finland, but Mustila has specimens growing on Etelärinne (Southern Slope), among them one that is probably the biggest and oldest in Finland. In America the species spreads easily through seed, and escapees have also been noted south of the Baltic, but not at Mustila or elsewhere in Finland.