Articles
VARIATION WITHIN THE BLACKBERRY GROUP UNDER EXTREME CLIMATIC CONDITIONS IN FINLAND
A few species of blackberries have, however, long been grown in sheltered gardens in Finland with surprisingly good results.
Presently the stock is poorly available, only a few varieties being offered for sale.
A thorough search within the potential growing area has revealed roughly a hundred cultivated clones representing eleven species, nine of which have been identified.
An additional hybrid, Rubus ulmifolius x Rubus idaeus, was found amongst clones.
Identification was based on the growth habit and flowering, which reveals most of the distinctive features.
Hence clones which did not flower were difficult to identify.
The blackberry is native to Finland only in the southwestern islands, where the species are R. caesius and R. pruinosus.
It seems that the non-native species, R. allegheniensis and the hybrid mentioned above have the best chances of surviving.
Both are relatively common in the circumpolar regions.
The species, characteristic of temperate regions, cannot be generally recommended for cultivation in Finland, although the country’s rich variety of soil and microclimatic conditions may allow some types to perform well in favourable locations.
The biggest problem is the short growing season, which does not permit most of the fruits to ripen.
Frost is seldom fatal.
During favourable seasons, some varieties can be very high yielding, when suitable methods of cultivation are used.