Fruit and Nut
History
The European plum and its sister the gage are cultivated forms of Prunus domestica, a tree native to Southern Europe and Western Asia. Gages are a small, very sweet and juicy plum, typically green or golden in colour. In fruit jargon, the word 'plum' is reserved for non-gage forms of Prunus domestica. The fruit are typically red or purple, but some cultivars are green or yellow. The distinction between plums and gages is somewhat arbitrary as they cross-pollinate readily and sometimes look and taste very similar. Plums and gages are mostly eaten fresh. However, some cultivars are particularly suited for cooking.
Damsons are a cultivated form of Prunus insititia, thought to have reached Europe from Damascus (Syria) in pre-Christian times. Damsons are smaller and generally less sweet than plums. They are also much hardier and will grow successfully on difficult or exposed sites. They are used more for cooking, though can be very tasty when fully ripe. Damsons are mostly self fertile, though will also cross-pollinate with plums and gages.
In many parts of the world, notably Serbia and Hungary, native plums are distilled into powerful spirits. Šljivovica (plum brandy) is the national drink of Serbia. The Hungarian equivalent is called palinka.
The plum is closely related to the apricot (Prunus armeniaca) and peach (Prunus persica), and numerous intermediary forms such as Prunus simonii, the Apricot Plum. Prunus salicina, an Asian plum native to China and Japan, has been in cultivation for thousands of years and was mentioned in the songs and writings of Confucius (551 BC – 479 BC). Although Pompey the Great is credited with introducing the cultivated plum to Rome in 65 B.C., it is likely that wild plums were used by the peoples of southern Europe for many thousands of years.
Like most fruit, plums are low in calories, protein and fats. 100g of fresh plums (stone removed) contains the following:
Carbohydrate 11 percent
Protein <1 percent
Water 87 percent
Fats negligible
Calories 45
100g of fresh plums also contain 350 IU Vitamin A, 10mg Vitamin C, 6 µg Vitamin K, 150 mg of potassium and smaller amounts of B vitamins and other minerals.
Modern varieties
Nowadays there are many hundreds of plum cultivars worldwide. The Agroforestry Trust Plum Directory documents almost 300 distinct cultivars and the list is far from complete. It is likely many times this number of local varieties exist in Europe and Asia, particularly in mountainous areas where a particular cultivar may be confined to one or two valleys.
Plum cultivars rarely come true from seed but instead are propagated by layering or taking cuttings. Nowadays, commercial plum cultivars are grafted onto specialist rootstocks chosen for particular characteristics. In countries where the plum has been cultivated commercially, there has been considerable development of rootstocks over the last one hundred years. The Plum Directory identifies almost fifty different rootstocks in Europe and North America. The most common rootstocks used in Ireland and the UK are Pixy, St Julien A, Brompton, and Myrobalan B. Their characteristics are as follows:
Pixy: Very small trees suitable for urban gardens; fruits early in life; needs good soil to do well
St Julien A: More vigorous tree growing to 3-4 meters; fruits early in life; more tolerant of poor soils than Pixy
Brompton: Vigorous tree tolerant of most soils and situations; very strong roots; susceptible to some diseases.
Myrobalan B: Extremely vigorous tree; more disease resistant than Brompton; induces later ripening; incompatible with some cultivars.