Cherimoya

What is a cherimoya?

The cherimoya is a small fruit tree of the custard apple family, the Annonaceae. Its heart-shaped or rounded fruit has a green skin patterned with scale-like marks and a white, creamy, sweet flesh in which large black seeds sit. Of its many tropical relatives it is the one from the mountains: it prefers mild temperatures and does not succeed in the hot, humid lowlands. That makes it one of the few annonas suited to subtropical and Mediterranean regions.

Origin and growth

The cherimoya grows wild in the valleys of the Andes, at moderate altitudes with mild, even temperatures. For a long time this was regarded as its homeland. A genetic study published in 2017, based on 1,765 trees from six countries, places its origin in Mesoamerica instead, with a spread to South America in pre-Columbian times.

The tree grows to 5 to 9 metres, upright but branching low, often somewhat shrubby. Shortly before flowering in spring it sheds its leaves for a short time. The flowers are fleshy, greenish and fragrant, and appear with the new leaves.

Requirements

Climate. Subtropical to mild, without extreme humid heat. Strong wind interferes with pollination and fruit set.

Cold. Light frost is tolerated. Morton gives about -3 °C as the limit; a few degrees lower can severely damage mature trees.

Water. Regular, moderate water during flowering and fruit growth in summer; no waterlogging.

Soil. Light to heavy soils are possible; best is a medium soil of moderate fertility with good drainage and a pH of about 6.5 to 7.6.

Light. Sun to light half shade; young trees appreciate protection from the strongest summer sun.

Fruit, use and harvest

The fruit is picked when mature but still firm and ripens within a few days; ripe cherimoyas bruise easily. The flesh is eaten raw with a spoon. Its seeds are poisonous: they contain alkaloids, have been used crushed as an insecticide and can seriously damage the eyes. They are spat out whole and never chewed.

Because the flowers are protogynous, the female phase comes before the male one, and few insects visit them outside the homeland, natural fruit set is often poor. In Spain hand pollination with a fine brush is common practice. It must happen in a window of six to eight hours, when the stigmas are white and sticky.

In the food forest

In a food forest the cherimoya belongs to the small tree layer, beneath and between the large canopy trees. The short leaf drop before flowering lays a layer of mulch at its foot each year. Its sensitivity to wind and strong sun in the early years makes it a good candidate for planting in the lee of faster nurse trees and windbreaks. In a plant guild it combines well with low, flowering plants that attract small insects, even though they will not replace hand pollination.

In the Mediterranean climate

The Costa Tropical between Granada and Málaga is the most important cherimoya area in Europe. Andalusia had about 3,000 hectares of cherimoya in 2018, 94 percent of the Spanish area, mostly in low valleys between 25 and 250 metres above sea level, and the fruit carries a protected designation of origin. Almost all of it is the variety Fino de Jete. Between 2014 and 2018 the area shrank slightly, while avocado, mango and loquat gained ground in the province of Málaga. In southern Italy the cherimoya, known there as annona, has been grown on the coast around Reggio Calabria since the nineteenth century; according to Vittorio Farina of the University of Palermo, Calabria and Sicily together have about 100 hectares. On a plantation near Orosei, about two hours north of Sa Medada, cherimoyas have been bearing fruit for years.

What the Spanish experience shows is that the cherimoya suits a coastal Mediterranean climate with mild winters better than many tropical fruit trees, provided it has shelter from wind and regular water in summer. The cherimoya is not on the EU list of invasive alien species.

Propagation and care

Varieties are grafted onto seedling rootstocks, usually after 12 to 24 months. Seeds remain viable for several years when stored dry and germinate in three to five weeks. Young trees are protected against frost and wind. Light pruning keeps the tree low enough for hand pollination and harvest.

How Terra Humana understands it

At Sa Medada the cherimoya is a mountain fruit among the tropical ones: closer to the Mediterranean climate than mango or papaya, but dependent on care for its flowers. It is meant to find its place in the protected middle layer of the planting. Whether its fruit sets here naturally, or only with a brush, is one of the questions we want to answer by observing it.