Duo of Pistachio trees - Pistacia vera Kerman (female), Peters (male)

This pair of male 'Peters' and female 'Kerman' pistachio trees allows for a bountiful harvest of pistachios in late summer. They should be planted in the garden with the male tree positioned so that the prevailing wind carries its pollen to the flowers of the female tree. The pistachio tree is a small tree with clear requirements for climate and soil: it prefers sandy-loamy, limestone soils that are deep and well-drained, and thrives particularly well in a continental Mediterranean climate where summers are long, dry, and hot, and winters are dry and quite cold. Planting is best done in autumn.

The pair consists of:

- x 1 Female 'Kerman' Pistachio Tree: the most widely cultivated variety of pistachio, prized for its hardiness and productivity. The tree blooms abundantly around mid-April and produces large clusters of round, large fruits that become vibrant when ripe, between late August and September. Beneath the fleshy, aromatic, and highly coloured "skin" lies a large, green, nutritious, and tasty nut, protected by a whitish skin that hardens and opens when ripe. This is what we consume, fresh or roasted, salted or unsalted. The mature tree is hardy down to -15°C, and it blooms around mid-April. The first harvests will be possible on trees aged 5 to 6 years. The harvest can be more or less abundant depending on the year, or sometimes even absent.

- x 1 Male 'Peters' Pistachio Tree: an excellent pollinator for 'Kerman' and several other female varieties. The tree is hardy down to -15°C, heat-resistant (up to 45°C), vigorous, and it blooms quite young, around the age of 4 years. Its flowering, which lasts for 3 weeks between April and May, usually avoids the frost in its cultivation zone and overlaps with that of various female varieties. One tree can pollinate 5 to 8 female pistachio trees.

The true pistachio tree (Pistacia vera) belongs to the Anacardiaceae family, just like Pistacia lentiscus (Mastic Tree) and P. terebinthus, the mango tree and the cashew nut tree. It is a dioecious tree, meaning that there are female trees (like 'Kerman') and male trees (like 'Peters'). Its growth is slow, but it can live for several centuries. Seedling trees do not bear fruit until the age of 8-10 years. Grafting can shorten this period by about 3 years. The most common rootstocks are UCB1, Pistacia terebinthus, and its hybrid with P. lentiscus called P. x saportae.

The pistachio tree is a deciduous tree that can reach a height of 4 to 6 m with a spread of 3 to 5 m. Its habit is slightly weeping in female pistachio trees, but upright in male trees. The leaves are compound, with 3 to 5 (7) broad, fairly dark green leaflets. The flowering occurs before the appearance of leaves, in spring. Male trees have dense clusters of flowers, while female trees have large, slightly loose, and trailing clusters. The abundant pollen is carried by the wind.

For pollination to be successful, it is essential to determine the direction of the prevailing wind when planting pistachio trees. It is also necessary to choose a compatible pollinator that will flower with the female trees. One male tree can pollinate 4 to 7 female trees.

The female 'Kerman' pistachio tree is pollinated by the wind: it is imperative to plant the male 'Kerman' tree facing the prevailing wind, in front of the female tree, so that its pollen is carried to the inflorescences of the latter. Prepare a large planting hole (50 cm in all directions) and space the trees 2 metres apart. The flowering of the pistachio tree is sensitive to frost, as well as to excessive moisture. Rain at the wrong time can compromise pollination. This fruit tree should always be planted in a sunny, well-ventilated, and airy location, never in damp, confined, or dark areas. A well-exposed slope seems ideal.

While not demanding, the female 'Kerman' pistachio tree will be more productive in soil that is not too poor. Adding potassium and magnesium can be beneficial, as well as applying organic fertiliser in late winter. To limit the alternate bearing phenomenon (fruit production every two or three years), it is useful to water the tree in spring, especially if it does not rain.

In favourable climate and soil conditions, this pair of pistachio trees can be planted in an orchard or in a large, free-growing, flowering, and edible hedge. On either side of the two pistachio trees, to avoid hindering pollination, you can plant, for example, the blackthorn, the bird cherry, the wild apple tree, the male cornel 'Jolico', or even strawberry trees.