Cherimoya (Annona cherimola) makes an outstanding small landscape tree for gardeners in frost-free areas. While the flowers may not be considered beautiful, they have a pleasant fragrance, and the foliage is attractive and green for most of the year. Cherimoya flowers are pollinated by hand because there are no natural insect pollinators in North America. The tree grows best in U.S. Department of Agriculture plant hardiness zone 10. It will also grow in zone 11, but it won't flower or produce fruit unless it receives 50 to 100 hours of temperatures below 45 degrees F in winter.
Water the cherimoya tree slowly and deeply every two or three weeks from April through November. The goal is to keep the soil moist but not wet or soggy. Discontinue watering from December through March to allow the tree to go dormant.
Feed the tree with 6-6-6 fertilizer four times a year. Use a total of 1/2-pound in the first year, dividing the fertilizer evenly over the four feedings. Use 1 pound the second year, and increase the amount by 1 pound per year until the tree receives a total of 5 pounds per year.
Suitable for: light (sandy), medium (loamy) and heavy (clay) soils, prefers well-drained soil and can grow in heavy clay and nutritionally poor soils. Suitable pH: acid, neutral and basic (alkaline) soils and can grow in very alkaline soils.
Prune young saplings, limiting them to two or three scaffolding branches. Choose three sturdy branches growing at about a 60-degree angle from the main trunk and 2 feet or so from the ground as scaffolding branches. Remove the other lateral branches coming off the trunk.
Blindness can result from the juice of the crushed seeds coming in contact with the eyes. The seeds and twigs contain several alkaloids including ( + )-reticuline, (-)-anonaine, liriodenine, and lanuginosine. Human ingestion of 0.15 g of the dark-yellow resin isolated from the seeds produces symptoms resembling the effects of atropine.
