The plum, a high food-value fruit, should be represented in every garden. Dessert, jam, tarts – it is called upon to fill very important roles. If there is no room for a standard or half-standard tree, then space might be found for a bush tree or a pyramid, and vacant wall space could be filled to great profit with a fan-trained plum.
Fruiting-size trees in 12-in. pots for the greenhouse can be purchased; general management is explained in the section FRUIT IN THE GREENHOUSE.
Ready for Use. Ripening dates for different varieties range between mid-July and October.
Dessert Varieties. Fruitgrowers’ catalogues contain long lists. A selection would include Early Laxton, excellent also for cooking, and the earliest to ripen – in mid-July; Oullin’s Golden Gage, early August; Purple Pershore, mid-August, useful also for cooking; Denniston’s Superb Gage, mid-August; Early Transparent Gage, August; Greengage, excellent also for preserving, late August; die famous old favourite and always dependable Victoria giving immense crops as useful for cooking as for dessert and ripe in early September; Coe’s Golden Drop, October.
Cooking Varieties. These include Czar, mid-August; Belle de Louvain, late August; Pcrshore Yellow, August to September; Monarch, for dessert also, late September.
Wall Plums. Grown as fan-trained trees against a north-facing wall the following give magnificent fruit: Czar, Victoria, Monarch, Ouliin’s Golden Gage. Against an east-facing wall: Victoria, Coe’s Golden Drop, Monarch. Against a west-facing wall: Czar, Victoria, Early Transparent Gage. Against a south-facing wall: Coe’s Golden Drop, Early Transparent Gage, Greengage, Denniston’s Superb Gage.
Mates for Plums. Many varieties of plum are self-sterile, requiring pollen from a different variety to set their fruit. So unless there are other plum trees in the immediate neighbourhood it is safest to plant more than one variety; bees and other insects will effect the necessary transference of pollen during their busy rounds.
There are, however, certain varieties that are self-fertile and can be planted singly; their own pollen does all that is required. This applies to most of those in the foregoing lists. The self-fertile ones include Early Transparent Gage, Oullin’s Golden Gage, Denniston’s Superb, Purple Pershore, Pershore Yellow, Victoria, Czar, Belle de Louvain, Monarch.
Soil Preparation. A chief requirement is sufficient lime in some form. If this is lacking it should be worked into the ground as broken chalk, or mortar rubble, or slaked or hydrated lime. Ground inclined to lie wet in winter needs to be dug at least 2 ft. deep over as large an area as is practicable for one or more trees, and plenty of mortar rubble or broken chalk, and sand or grit worked deeply into it. This will improve the drainage and provide the necessary lime; or the latter can be added as slaked or hydrated lime.
If the ground is sandy or gravelly it must be given body by the addition, during deep digging, of be caused by too rich soil, overfeeding, or feeding before the fruiting habit has been properly formed, or by a too loose root-run. The remedy is to prune the roots, as explained in the section THE How AND WHY OF PRUNING. The check thus given induces the formation of fruiting wood and lessens the production of mere wood growth.
Propagation. Plum trees are increased by budding or grafting chosen varieties on to specially selected stocks. How this is done, and young trees trained to the desired form or shape, is explained in the section How TO PROPAGATE FRUIT TREES AND BUSHES.
Insect Pests. A general clearance of pests can be made by spraying the trees with a tar oil winter wash, any time between early December and late January, 1 pint of the wash to each 2 gals. of water. This clears stems and branches of hibernating insects, insects’ eggs, moss and lichen. In the case of wall plums the spraying should be done before the end of the year, the buds generally being in a more advanced stage in that sheltered position than on trees in the open. This treatment is to be carried out only when the buds are completely dormant, or they will be injured.
Trees that were attacked by red spider during summer should be sprayed the following spring, after the petals have fallen from the flowers, with lime-sulphur solution, pint of the lime-sulphur to 3 gals, of water.
How these sprayings are carried out is explained in the section How TO DEAL WITH FRUIT PESTS AND DISEASES.
Thinning the Fruits. Plum clusters within reach are all the better for thinning out. If best-quality fruit is wanted the plums should remain not closer than about 2 in. apart. If the grower of choice dessert plums is satisfied with something less than the best the clusters should be thinned out so that, at the very least, no two plums touch one another.
If bulk is the main consideration clusters may be left somewhat thicker, but it must be remembered that a very heavy crop one year nearly always demands its price the next. That price is a next-year crop as small as its immediate predecessor was large.
Even after a moderate thinning the branches of some varieties of plum – the more straggly growing standards and half-standards – may be so weighted down with fruit that some support is necessary. These bowed-down branches should be held up with notched props placed in position before – not after – bark cracks.
Weighted shoots that cannot be thus propped should be supported in some other way. Generally it is possible to tie them to canes or stakes secured to adjoining branches; or thick string or tarred twine can be passed from branch to branch and the too-heavy shoots looped to these lines.
Plum wood is brittle, and surprisingly ready to break.
Gathering the Fruit.
Harvesting plums is a dry-weather job, less for the comfort of the picker than for the sake of the fruit, especially if this is to be kept for any length of time.
To expedite the work, cooking varieties might be shaken from the branches. But- their value is lessened by rough treatment, and careful picking from a pair of steps, or from a ladder (the top part padded with sacking to avoid injuring bark where the ladder rests), has its own reward.
Dessert varieties should always be hand picked, and so that the attractive bloom shall not be rubbed from the skins they should be handled by the stalks only.
Storing for Winter.
Some late varieties, such as Coe’s Golden Drop, keep well if put away dry in a dry and sunless room or other place, in shallow boxes, single layers if possible. None should be over-ripe and all should be thoroughly sound. They must be watched for signs of decay.
Plums can also be dealt with as explained in the section EASY HOME PRESERVATION OF FRUITS.
Preparing for Table.
Plums for dessert should retain their stalks and be placed on a leaf-lined fruit dish. Their attractive appearance depends largely on the bloom on their skins; this should not be spoiled by hurried, last-minute handling. Their food value is considerable and they have a laxative effect. They should not be eaten raw when overripe – a warning too often disregarded, especially with regard to greengages – and it is well to remember that the uncooked skins are by no means easily digestible.