Prunus is a genus of plants that includes apricots, peaches and blackthorn, as well as the familiar flowering cherries dealt with here. P. triloba is a flowering cherry which does best on a wall, preferably fan-trained, as it is doubtfully hardy in some districts, and in any case produces far moreon a sunny wall. The species carries single flowers, and is seldom seen. The Chinese cultivar ‘Multiplex’ is the variety commonly available. It grows to 3.6m (12 ft) or more on a sunny wall and carries masses of large double pink flowers from the end of March.
P. cerasifera, the cherry plum, is an excellent screen tree, growing to 6m (20 ft) or more. It carries white flowers in February and March and eventually small cherry-plums. The cultivars, which can be mixed in with the species in the screen, have different colours: ‘Atropurpurea’ has purple adult, and ‘Nigra’ purple leaves and pink flowers. The cherry plum is deciduous, but another prunus, P. laurocerasus, the cherry laurel, is evergreen, and therefore more commonly planted for screening. It is fast-growing to 5.5-6.0 m (18-20 ft), and produces candles of white flowers in April, and fruit similar to cherries which are red at first and turn black as they ripen. There are a number of named cultivars, only one of which, ‘Rotundifolia’, is suitable for screening, the rest being too low-growing.
General care: Prunus are happy in any ordinary, well-drained garden soil, and most prefer a trace of chalk in it, but P. laurocerasus, untypically, tends to be lime-hating. This species should be planted in April, the remainder in October. For hedging, plant 60 cm (2 ft) apart, and for screening 1.5m (5 ft) apart,back the tips of the shoots if planting for hedging. back hard as soon as the flowers are finished, on P. triloba as well as the screening prunus, to encourage young flowering shoots for next year, and use secateurs to trim the screening prunus if they need it, rather than hedge trimmers.
Propagation: The species are best grown fromsown outdoors as soon as it is harvested. Cultivars must be grown from taken in August and rooted in a 50-50 sand and peat mixture.
Pests and diseases: Birds eat the flower buds. Try net, or cotton. Blackfly should be sprayed with malathion. Peachcurl may be controlled by spraying with Bordeaux mixture in the winter. P. laurocerasus may get powdery (dust with sulphur) or leaf spot (spray with a fungicide).
This is the great genus to which the cherries, plums, almonds and peaches belong, most of which are trees, but there are valuable shrubby kinds as well. Among the best known of them are the cherry laurel or common laurel, Prunus laurocerasus, and the Portugal laurel, P. lusitanica, both of which are vigorous evergreens capable of reaching 15 ft. or more and much planted as hedges or screens. Both will grow in all reasonably fertile, not too dry soil, in sun or shade, the common laurel being particularly well able to survive in very shady places and in cities, though grime does spoil the appearance of its large glossy green leaves. Both plants have spikes of white flowers, those of the common laurel appearing in April, those of the Portugal laurel in June. Both also have useful varieties, azorica being a particularly large-leaved, handsome-flowered form of Portugal laurel, and Otto Luyken, a short (4 ft.) free-flowering form of the common laurel. All can be pruned in May as necessary to keep them in bounds, or can be lightly trimmed any time in summer.
Prunus glandulosa albiplena is a small bushy cherry, 4 ft. high, with double white flowers in April. P. cistena looks like a dwarf version of the purple-leaved plum, has similar white flowers in spring and reddish-purple leaves and makes an excellent 3 to 5-ft. Hedge. P. incisa can also be used as a hedge and covers itself in March with small white flowers as freely as a sloe. P. tenella Fire Hill is a dwarf almond with small deep rose flowers in March. P. triloba needs a warm sunny place to ripen its wood and produce its very beautiful double pink flowers in spring. All these are deciduous and succeed best in good, fertile, neutral or alkaline soil and a sunny place.