this genus brings together some plants of Mediterranean and Asian origin, not much used as bonsai, but which offer interesting characteristics, not very suitable for a beginner. Pistachios have a moderately rapid growth, the stem is generally twisted and branched in a dense and disordered manner; the bark is gray or brown, with age it tends to flake and become wrinkled; the crown is roundish, umbrella-shaped. P. vera, the plant that produces edible pistachios, has leathery, thick, compound leaves, consisting of small oval leaves; P. chinensis has compound leaves, light green in color, consisting of small lanceolate leaves; both of these essences have deciduous leaves, which become yellow or red in autumn, before detaching from the plant: They produce small greenish or yellow-pinkish flowers, in summer, followed, in the female plants, by bunches of fruits, which contain a single seed. P. lentiscus has very small, evergreen leaves, of a bright dark green color. The pistachio leaves and flowers are delicately scented.
these plants can be pruned throughout the year, practicing training pruning preferably in autumn or early spring; in general, pistachios do not tolerate vigorous pruning very well, it is therefore good to avoid exceeding large branches. The buds are trimmed, from April to October, leaving one-two leaves. The wire can be placed on the plant all year, avoiding massive interventions, or very tight ligatures, which can mark the bark for many years.
lay in full sun all year long; young plants should be lightly shaded during the hottest months of the year. Pistachios can generally withstand short periods of intense cold, but they should be repaired in a cold greenhouse, or placed in a sheltered position, for example against a house wall, covering them with TNT, from December to March.
in nature they endure even long periods of drought without problems; in pot it is good to water regularly, from March to October, but leaving the substratum well dry between one watering and another; in July-August it is good to intensify watering, wetting the soil thoroughly. In the cold months water sporadically, only in the case of long periods with no precipitation. In March and in autumn it is good to provide a non-excessive dose of slow release granular fertilizer, rich in nitrogen.
Pistachio - Pistacia vera: Other tips
Soil: use a rich, loose and very well drained substratum; an ideal mixture can be prepared by mixing a part of peat with two parts of sand and three parts of clay. However, these plants are generally known to adapt to various soil conditions. The growth is quite vigorous, so it is good to repot the young plants every year.
Multiplication: by seed, or by cuttings in spring.
Pests and diseases: pistachios are generally not affected by pests or diseases; poor ventilation can cause the attack by the cochineal, while excessive watering or poor drainage of the soil can favor the onset of root rot.