Pistachio

Where it grows

The pistachio was domesticated in northern Iran and Central Asia, where its wild progenitors still grow in the cold desert mountain foothills. It tolerates extreme heat and cold but needs hot dry summers and is very sensitive to humidity, restricting commercial cultivation to a narrow climatic band. Iran, the United States, and Turkey are the top producers.

How to recognise it

A small spreading tree with greyish bark and compound leaves of three to five leathery oval leaflets. Pistachios are dioecious, with separate male and female trees; growers plant one male per ten females for wind pollination. The fruit is a single-seeded drupe whose woody shell splits naturally along the suture as the kernel matures — the classic “smiling” pistachio.

Uses

Pistachios are eaten salted from the shell and shelled into baklava, mortadella, and the famously green Persian and Sicilian ice creams. Iranian gaz nougat, Turkish lokum, and Aleppo pastries all depend on the nut. The deep green kernel colour comes from chlorophyll and is sometimes used as a natural food colourant.

Lifespan

Healthy pistachio orchards can crop heavily for over 100 years, but the trees show strong alternate-bearing patterns from year to year.