Few fruits are as sweet as the sugar apple (Annona squamosa), famous in Brazil and other tropical countries, growing in U.S. Department of Agriculture plant hardiness zones 10 and 11. Temperatures below 30 degrees Fahrenheit damage or kill the trees, but they adapt very well to being grown in containers and can be brought indoors when freezing weather threatens.
Select an appropriate container for growing your sugar apple tree. A 10-gallon size is fine to start with, but the trees will need to expand into about 20 to 25 gallons after the first couple of years. A half wine barrel planter works well.
Fill the container with potting soil and plant the tree so that the top of the root ball is level with the top of the potting soil. The soil level in the pot should be about 3 inches below the rim of the pot. Add 2 inches of mulch over the surface of the soil to help conserve moisture. Make sure the tree is in the center of the container and stands with a straight trunk.
Place the potted sugar apple tree in a location that receives at least 6 hours of sun per day; fruit set is increased with greater sun exposure. Select a location for the planter to accommodate your tree growing 8 to 10 feet tall and wide.
Water frequently in the spring and summer months when flowering and fruiting occur. To encourage maximum fruit size and quality, water the container whenever the top half-inch of soil is dry during this period. Reduce watering after the fruit is harvested in the fall. Allow the the top two inches of soil to dry between waterings during the tree's dormant period.
Apply one-quarter pound of a complete balanced fertilizer every 6 weeks during the first growing season. Increase to one-half pound per application in the second year and one pound in the third and subsequent years. Begin fertilizing when the flower buds appear each year and stop after the fruit has been harvested.
Prune the tree in late winter or early spring each year, just before the flowers emerge. Sugar apple trees grown in containers need significant annual pruning to maintain the desired size. Cut back at least 30 percent of the previous year's growth and thin out interior branches so that light can penetrate to the wood in the middle.
Cover or move the trees indoors at night when temperatures below freezing are forecast. Young trees are damaged at 32 F and mature trees are damaged at 28 F. Covering with a large tarp can add a few degrees of protection, but at temperatures below 25 F, the potted trees need to be brought into a garage or other protected space to prevent frost damage.