How to grow Custard Apple

Where to plant

Custard apples need warmth, full sun and well drained soil. UF/IFAS gives ideal temperatures of about 72 to 94°F (22 to 34°C), high humidity at flowering, steady moisture from flowering to harvest and a dry spell for a few months before spring bloom. Flooding for as little as 7 to 10 days can kill trees, so avoid low, wet ground. Young trees establish best out of the wind.

Sugar apple and atemoya suit South Florida and Hawaii, and atemoya copes best in warm, sheltered spots in Central Florida, where young trees need covering on frost nights. Cherimoya does best in mild coastal Southern California gardens sheltered from wind. North Florida, the Gulf Coast, Texas, the desert and the Pacific Northwest are too cold except in a container moved under cover, and the rest of the country needs a heated greenhouse.

Choosing a variety

Sugar apples are mostly grown from seed of selections such as Thai Lessard (green) and Kampong Mauve (purplish red), which come fairly true. For atemoya, UF/IFAS rates Gefner the most satisfactory in Florida: it does not need hand pollination and gives good fruit. Page crops well but fruit tends to split, and African Pride and Bradley set few fruit without hand pollination.

How to plant

1. Buy a grafted tree (or a seedling sugar apple of a good selection) from a Florida or local fruit nursery.
2. Plant in spring in full sun, at least 15 to 20 feet (4.5 to 6 m) from other trees, buildings and power lines.
3. Set the tree at the depth it grew in the pot, backfill with native soil and water well.
4. Mulch around the tree, keeping the mulch a few inches from the trunk.
5. Remove any fruit that sets in the first year or so, so the tree grows strongly.

Watering and feeding

Keep the soil moist from flowering through harvest, and water young trees regularly in dry spells. UF/IFAS notes a few months of drier conditions before spring bloom suits the trees. Do not let lawn sprinklers on a timer keep the root zone wet, as too much water too often causes decline.

Feed young trees regularly for vigorous growth. From about the third year, reduce how often you feed, which helps flowering and fruit set. Avoid heavy lawn fertilizer near the tree, which can reduce fruiting.

Pruning and care through the year

• Natural fruit set is often under 3 percent because the small sap beetles that pollinate the flowers are scarce. UF/IFAS notes hand pollination can raise fruit set to nearly 100 percent: collect pollen from wide open flowers in the male stage in the late afternoon or evening, and the next morning dab it with a small brush onto the glistening centers of barely open flowers in the female stage.
• Strong winds with heavy crops can break limbs, so train young trees to a sturdy framework and plant out of the wind.
• Cover young trees on frost nights in Central Florida.

Harvesting

Do not pick immature fruit; it stays hard, browns and rots. As fruit matures, it turns from green to yellowish green, the areas between the bumps swell and turn pale, and a white or bluish bloom appears. Purple types darken and turn bright pink between the bumps.

Ripen picked fruit at room temperature until soft, then refrigerate; ripe sugar apples keep only 2 to 4 days. Atemoya is harvested mainly from August to October in Florida. Eat the pulp fresh with a spoon, discarding the seeds, or blend it into ice cream and shakes.