Plums require a light soil such as sand, gravel or chalk. The latter is the most suitable, as a certain amount of lime is necessary. Sandy and gravelly soils need to have lime added at the time of planting. Mortar rubble is a convenient form, and each autumn in the following years hydrated lime can be applied to the surface soil.
This should be applied at the rate of lb. per square yard. Scatter it on the soil surface under the trees to the extent of the branches.
Lime or any of the fertilizers should not be heaped round the bole of a plum tree as it is the tips of the roots that are the feeding organs. As the branches extend, so do the roots. Thus, the spread of the branches indicates approximately the position of these root tips under the soil.
Liming promotes stoning in plums, and although the fruit may set it will not mature if there is lack of lime. Fertilizers must be given in addition to keep a healthy balanced tres increasing in size gradually each year, and at the same time bearing regularly. Suitable fertilizers are nitrate of soda and sulphate of ammonia. Care must be taken using these manures, and no dressing given if the trees become sappy and produce too much leaf growth.
Like apples and pears, plums are grafted, and in this case a wild plum is used. The two types selected and now used by all good nurserymen are Myrobalan B, for vigorous trees, and the Common Mussel, for dwarf trees.
Plums are most frequently grown as standards, although for limited space bush trees can be had. For walls they may be trained as fan-shaped trees, and in this case a south or west wall must be selected as plums bloom very early in the year. In other aspects they would be liable to damage by cold winds and frosts.
Plums grown as bushes are convenient where space is very limited or where the shadow cast by a large standard would be a nuisance.
For bush trees choose varieties grafted on to the Comrhon Mussel stock.
Varieties for standards or bushes.
Dessert : Oullin’s Golden Gage, Dennis-ton’s Superb, Early Transparent Gage, Jefferson, Reine Claude de Bavay, Coe’s Golden Drop, Comte d’Althan’s Gage, Pershore, Late Transparent. Cooking : Czar, Purple Pershore, Victoria.
Varieties for growing on a wall or fence.
South aspect : Early Transparent Gage, Denniston’s Superb, Jefferson, Coe’s Golden Drop, Reine Claude de Bavay, Golden Transparent. North aspect : Czar, Victoria, Oullin’s Golden Gage. West aspect : Early Transparent Gage, Oullin’s Golden Gage, Denniston’s Superb, Jefferson, Victoria, Czar. East aspect : Comte d’Althan’s Gage, Victoria, Coe’s Golden Drop.
Varieties of spreading growth.
Red plums : Comte d’Althan’s Gage, Victoria. Yellow plums : Coe’s Golden Drop, Pershore. Purple plums : Czar, Purple Pershore.
Varieties of upright growth.
Yellow plums : Denniston’s Superb, Jefferson, Late Transparent, Oullin’s Golden Gage, Reine Claude de Bavay.
Pollination. “No fruit following excessive flowering” is the complaint of numerous amateur plum-growers. The importance of pollination must be remembered. Only three of the best varieties are self-fertile. These are Czar, Purple Pershore and Victoria. All others must be cross pollinated with another plum nearby. Unless bees and other insects can carry pollen from one to the other, no fruit will set, however freely blossom is produced.
Damsons require a similar soil to plums and general treatment is also the same. In windswept gardens they are frequently used as shelter trees. They will withstand gales, and if planted along the boundary of the garden will provide a certain amount of protection for other plants and trees.
The trees require little attention and no pruning is necessary beyond the occasional removal of dead or badly placed branches. Paint over any large wound made with tar or specially prepared paint to keep out the spores of fungus diseases which can enter the healthy wood through newly-made cuts.
Varieties of damsons. Aylesbury Prune, ready. October to November ; large fruit, reliable cropper. Bradley’s King of the Damsons, ready September ; medium size, good flavour. Farleigh Prolific, ready September ; small, poor flavour, very heavy cropper. Merry-weather Damson, ready September ; very large fruit, used for cooking Shropshire Damson, ready September ; large fruit, best for jam.