Soursop Trees

Soursop trees are also known as graviola or guyabano trees. Hardy to U.S. Department of Agriculture plant hardiness zones 10 through 11, the soursop tree is capable of reaching 25 to 30 feet tall when mature. The inside white part of the soursop fruit are mostly seedless, although there are a few seeds in the center. These seeds and the bark from the tree are toxic and contain poisonous alkaloids such as anonaine, muricine, and hydrocyanic acid. The name, soursop is derived from the Dutch zuurzak which means “sour sack.”

This tree is tolerant of many different types of soil, although it flourishes in well drained, semi-dry, sandy soil with a pH of 5-6.5. In Florida, it is commonly grown in the porous limestone. As a tropical tree, it does not tolerate cold or strong, sustained winds.

Soursop tree care involves a lot of mulching, which benefits the shallow root system. Soursop trees should be irrigated regularly to prevent stress, which will cause leaf drop.

In terms of fertilizer, the Soursop does well with 10-10-10 granular fertilizer every quarter of the year. Very little pruning is required of the trees once the initial shaping is reached. Remove dead, weak or diseased branches from the soursop tree in the spring before the leaf buds open. The mealybug is a common pest in Florida, where the tree is often infested with scale insects.

Fruit from soursop trees can be harvested when it is firm and yellow-green in color. They are soft enough to yield to the slight pressure of one's thumb. If allowed to soften on the tree, it will fall and crush. It is easily bruised and punctured and must be handled with care. Firm fruits can be held a few days at room temperature. Soursop can be eaten fresh or used in many desserts.