This section is from the book "Commercial Gardening Vol3", by John Weathers (the Editor). Also available from Amazon: Commercial Gardening, A Practical & Scientific Treatise For Market Gardeners.
This is a kind of small plum, a cultivated form of Prunus insititia, from which the Bullace is also derived. It is distinguished by oval and not roundish fruits, of a deep blackish-violet colour, with a heavy bloom when ripe. The trees naturally prefer moist situations, such as near the banks of running streams, etc, and they attain a fairly good age before coming into bearing.
Damsons are often planted round a plantation on the outsides, sometimes actually as a hedge. The idea, perhaps, is that from their rough acid flavour, when uncooked, there is less likelihood of the public helping itself. But as they are terribly subject to Aphis attack it is a bad plan, unless the grower makes up his mind to repel the Aphis; if he does not, the whole plantation may be infested from them. A variety named "Damascene" is grown in Worcestershire. Some say it was brought home from Damascus by the Crusaders. Other useful varieties are the "Farleigh Prolific" or "Crittenden", a heavy cropper, but one that some jam makers will not accept as a Damson. The "King of the Damsons" is a spreading tree, with large fruit, borne singly, not in clusters. Very apt to crack if not gathered in time. [w. g. l.]
Fig. 365. - White Bullace.
The Bullace is a form of the Wild Plum (Prunus insititia) found in the hedgerows and copses of Britain. The fruit is larger than that of a Damson or a Sloe, but is smaller than most plums or gages, and is usually roundish in shape. For practical purposes the Bullace is treated merely as a form of the Plum, and when grown at all is treated in the same way. The best variety is probably the "White Bullace " (fig. 365), with yellowish-white fruits mottled with red on the sunny side. It is a very heavy cropper, and is generally in season at the end of October and early November. Other varieties are the " Black Bullace", "Essex Bullace", "Royal Bullace", and "New Large Bullace". [j. w.]