Things You'll Need
Balanced, water-soluble fertilizer
Pruning shears or loppers
Soursop trees, known botanically as Annona muricata, are flowering broadleaf evergreen trees that are native to the tropical regions of Mexico, Central America, South America and the Caribbean. In the United States, soursop trees grow best in United States Department of Agriculture (USDA) plant hardiness zones 10 and 11. Soursop trees are prized for their smooth, gray-brown bark, glossy dark-green leaves and sweet, exotic fruit, which can be eaten fresh or used in recipes. In the proper climates, soursop trees thrive with little care or maintenance.
Plant, or position soursop trees in full sun locations that receive bright, direct sunlight for six or more hours each day. Choose locations on the south side of your home to ensure that your trees receive plenty of warm sunlight, according to the Purdue University Agricultural Extension website.
Provide soursop trees with 1 to 2 inches of supplemental irrigation per week from early spring through summer. Reduce the frequency and amount of supplemental irrigation during periods of heavy rain and during the cooler winter months; in winter, water as necessary to prevent the surrounding soil from drying completely.
Spread a 3- to 4-inch layer of an organic mulching material in a 3- to 5-foot diameter around the bases of your soursop trees to help conserve soil moisture and prevent their shallow, fibrous root systems from becoming dehydrated during hot, dry weather. Add additional mulch throughout the growing season, as necessary, to maintain an at least 3-inch layer.
Fertilize soursop trees weekly from early spring through summer to encourage healthy growth and development, as well as prolific fruit production. Feed your trees with a diluted, half-strength solution of a balanced, water soluble fertilizer; consider using a fertilizer product that has been specially formulated for use with fruit-bearing or tropical trees. Follow the application instructions that were included with the fertilizer to avoid harming the trees' delicate root systems.
Prune your soursop trees every two to three growing seasons to control their size and shape, or as necessary to remove diseased, damaged, weak or crossing branches. Wait to prune soursop trees until after you have harvested their fruit to reduce pruning stress. Make your pruning cuts just outside of the branch collar and use sharpened and sterilized pruning shears or loppers to reduce the risk of the spread of botanical diseases.
Harvest fruit from your soursop trees when it is fully-grown, firm and yellow-green in color. Store the harvested fruit at room temperature for two to three days. After that, the fruit can be stored in the refrigerator for an additional two to three days.
Tropical soursop trees are susceptible to infestation by mealybugs, fruit flies, red spiders, lace-wing bugs and scale insects. Monitor your trees for signs of increased insect activity and contact your local agricultural extension office for treatment advice if the health of your trees is adversely affected.