Cultivated sour cherries were selected from wild specimens of
Prunus cerasus from around the
Caspian and
Black Seas, Schaerbeek cherries were devastated by the Napoleonic and World Wars. Today there are efforts to reestablish Schaerbeek sour cherries, a defining component of
Kriek lambic beer culture in Belgium recognized by UNESCO in 2016 as an "Intangible Cultural Heritage of Humanity." Although a "Morello type," Schaerbeek cherries are distinctive in that they are ovate on the horizontal axis, a deeper burgundy color when ripe, have a lower chill requirement to set fruit, and have a distinctive cinnamon aroma and flavor. In England, sour cherry cultivation was popularized in the 16th century in the time of
Henry VIII. They became a common crop amongst Kentish growers, and by 1640 over two dozen named
cultivars were recorded. Before the
Second World War there were more than fifty cultivars of sour cherry in cultivation in England; today, however, few are grown commercially, and despite the continuation of named cultivars such as 'Kentish Red', 'Amarelles', 'Griottes' and 'Flemish', only the generic Morello is offered by most nurseries. This is a late-flowering variety, and thus misses more frosts than its sweet counterpart and is therefore a more reliable cropper. The Morello cherry ripens in mid to late summer, toward the end of August in southern England. It is self-fertile, and would be a good
pollenizer for other varieties if it did not flower so late in the season. Sour cherries require similar cultivation conditions to
pears, that is, they prefer a rich, well-drained, moist
soil, although they demand more
nitrogen and
water than sweet cherries. Trees will do badly if waterlogged, but have greater tolerance of poor drainage than sweet varieties. As with sweet cherries, Morellos are traditionally cultivated by budding onto strong growing rootstocks, which produce trees too large for most gardens, although newer dwarfing rootstocks such as
Colt and
Gisella are now available. During spring, flowers should be protected, and trees weeded, mulched and sprayed with natural seaweed solution. This is also the time when any required
pruning should be carried out (note that cherries should not be pruned during the dormant winter months). Morello cherry trees fruit on younger wood than sweet varieties, and thus can be pruned harder. They are usually grown as standards, but can be fan trained, cropping well even on cold walls, or grown as low bushes. ==Production==