What is citrus?

Citrus is a group of evergreen trees and shrubs, grown for fruit whose peel is studded with oil and whose flesh is packed in juice-filled vesicles.

Citrus is a genus of plants belonging to the rue family (Rutaceae), yielding pulpy fruits covered with fairly thick skins. Britannica Economically important plants in this group include the lemon, lime, sweet orange, sour orange, tangerine, grapefruit, citron and shaddock. Britannica

Citrus plants are typically evergreen trees or shrubs with glossy oval-shaped leaves; many species have thorns. Britannica The flowers are usually white with five petals and are very fragrant. Britannica The fruits are a type of modified berry known as a hesperidium, and the flesh is divided into segments packed with tiny juice-filled vesicles. Britannica The peel, or rind, of the fruits is leathery and studded with oil glands. Britannica

Yuzu is the most cold-resistant of all citrus fruits, capable of growing at high altitudes at temperatures just above freezing, and is most commonly associated with Japan and Japanese cuisine. Britannica

The RHS, writing for UK gardeners, lists a wide choice of plants in this group.

The RHS lists a huge range of citrus plants to choose from, including lemons, oranges, mandarins, limes, grapefruits, kumquats, limequats, calamondin oranges, tangelos and citrons. RHS Citrus plants are self-fertile, meaning you only need one plant to produce fruit. RHS

Look next at growing citrus in the UK, or at types.