Sweetsop, Soursop, and Atemoya
Home-grown tropical fruits are one of the joys unique to Florida gardening. So-called "dooryard" mango, guava, avocado, and more thrive in the warmer half of the state. With vigilant cold protection, gardeners further north can grow some of these, too. And for the next addition to your home orchard, we have a couple suggestions from the genus Annona.
Three unusual but delicious tropical fruits are sweetsop, soursop, and atemoya. Sweetsop and sugar apple are common names for the tropical fruit species, Annona squamosa. Soursop, graviola, and guanabana are common names for a closely related species, Annona muricata. Both species are native to the American tropics, but not to Florida.
The botanical genus Annona contains dozens of other fruit tree species: cherimoya (A. cherimola), custard apple (A. reticulata), pond apple (A. glabra), and ilama (A. diversifolia), to name a few. Cross-pollinating A. squamosa and A. cherimola produces a seventh fruit: the hybrid atemoya.
The three Annona species below are small to medium trees. Sweetsop, soursop, and atemoya can reach 15 to 30 feet at maturity. As fruit trees they are usually pruned smaller. Reducing their size keeps the canopy healthy and the fruit within reach.
All three species are deciduous, losing their leaves in the cooler months. Their leaves are long, green, and smooth at maturity. The form is open, spreading, and upright with long, slender branches. Depending on pruning practices and site, the canopy can be round or asymmetrical.
Flowers on these species appear in spring and early summer, during the first flush of new growth. The flower petals are about an inch long, pale green, and fleshy. The blooms appear on year-old or new growth, so careful pruning is important. See the "planting and care" selection below for further pruning instructions. Annona species' fruits ripen in between late summer and early fall. Pick the fruit when it reaches full size but before it is completely ripe.
Sweetsop (sugar apple)
Sugar apple makes a beautiful small landscape tree. The fruits are aggregate (made up of many smaller sections) like raspberries. Sections of the fruit separate easily once the fruit is ripe. In shape, fruits range from round to conical. Inside the fruit, the pulp is white or cream with small black seeds. The custard-like consistency and sweet flavor earned this species the name "custard apple."
There are a number of cultivated varieties available but they differ in quality. Named for William Lessard, 'Lessard Thai' produces large, green fruits of excellent quality. 'LeahReese' is a large green fruit with excellent quality but flowers must be hand pollinated to produce adequate fruit. 'Purple', 'Red', and 'Kampong Mauve' have smaller, reddish to purple fruits. Unfortunately the seedless varieties available tend to have poor fruit quality. UF/IFAS does not recommend 'Cuban seedless' or 'Brazilian seedless'.
Another Annona species sometimes also called custard apple, is atemoya. Atemoya is a hybrid of sweetsop and cherimoya. In the landscape the hybrids generally grow into small to medium-sized trees. They can reach up to 30 feet if left unpruned. The fruits can grow up to six inches in diameter and often look like small artichokes. They have a sweet, custardy flavor with hints of vanilla, wintergreen, and pineapple.
Atemoya is more cold tolerant than sweetsop but is still damaged by temperatures below freezing. It will grow best along coastal areas in South Florida, from Sarasota and Merritt Island southward. Some cultivars may require hand pollination in order to produce fruit. To avoid hand-pollinating, choose the cultivar 'Gefner'.
Don't let the name fool you — soursop is a sweet and delicious fruit. The consistency is custard-like, similar to sweetsop. Soursop's flavor is what sets it apart. It has been described as a combination of strawberry, apple, and even citrus. Look for varieties called "sweet" as some cultivars are more sour than others.
Soursop is slightly less cold hardy than sweetsop and atemoya. They should be planted in warm sites that do not freeze or experience prolonged temperatures below 50F. Soursop is not a common commercial crop. As a result, there are few studies published and fewer cultivated varieties to choose from.
Planting and Care
The planting and care instructions for sweetsop, soursop, and atemoya are very similar. Plant them in full sun. Choose a site 15 to 30 feet from other trees, structures, and powerlines. In Central and North Florida, plant them in the warmest spot in your yard. A site that is convenient to protect from frost will save you trouble, too. As with most fruit trees, remove most of the fruits the first year. As disappointing as it is, removing fruit helps trees adjust after transplanting.
You can certainly start sweetsop and soursop from seed but be prepared to wait a few years for fruit. Starting with young trees instead means your first harvest will come sooner. Unlike sweetsop and soursop, atemoya is a hybrid. This means that its seeds will not produce trees and fruit like its parent. We suggest purchasing a grafted atemoya in a 3-gallon pot size. Check for pests and diseases and avoid root-bound trees.
All fruit trees need regular watering until they have become established. Afterwards they will still need occasional watering in drought conditions. Annona species are reasonably drought tolerant but the best fruit comes from trees that have not been drought stressed. Once fruit has set, occasional watering during dry periods will keep your fruit quality high.
For fertilizer, choose a balanced formula (or one with lower phosphorous). If the fertilizer you apply doesn't include micronutrients, supplement with these, too. Generally fertilizer is applied frrom April through September. As always, we recommend a soil test to determine which nutrients, if any, are required. These trees are not saltwater tolerant.
Once the tree stops producing fruit for the season, prune it to keep the branches from growing out of reach. The goal of pruning is to keep the tree small and open. Light should penetrate all the way into lower canopy. All three species discussed above are pruned to remain small trees, only 8-12 feet high. Plan to prune trees during the first or second week of March, when new growth is just emerging.
Before you prune, take a careful look at the most recent growth. Sweetsop, soursop, and atemoya produce flowers on year-old and new growth. Over-pruning might remove the young branches and leave you no flowers or fruit. Instead, in early spring, prune off only about a third of last year's growth. Reduce long shoots to two-thirds or half of their length. Also remove any dead wood. See our article on pruning deciduous fruit trees for more information.
The seeds and bark of sweetsop, soursop, and atemoya are considered toxic. Removing the seeds beforehand makes the fruit safe to eat. Still, be mindful of children and pets playing in the landscape.
Annona species are susceptible to several pests and diseases, too. Scout the tree often for signs of a problem. By far the most difficult pest is the annona seed borer. This insect's larvae develop inside the fruits. Bagging individual fruits will prevent this pest from laying her eggs. Scales, mealy bugs, and ambrosia beetles are occasional pests as well.
For more information on sweetsop, soursop, or atemoya, please contact your county Extension office.