Many types of interesting tropical plants exist, including the breadfruit tree (Artocarpus altilis), named for the starchy, white flesh of its bowling ball-sized fruits. It's native to Malaysia and other parts of southeast Asia, and quite frost-sensitive, only growing outdoors in U.S. Department of Agriculture plant hardiness zones 10 through 11, although dwarf cultivars can be container-grown and over-wintered indoors in colder areas. You can grow a good crop of breadfruit by paying attention to the tree's cultural needs.
Protect from Cold
The breadfruit tree is sensitive to both cold and extreme heat and does best when it's kept at a temperature between 60 and 95 degrees Fahrenheit. If you're growing the tree in a container, move it into a partially shaded spot if summer weather becomes especially hot to prevent leaf scorch from strong sun and high temperatures. The breadfruit tree can't survive temperatures that drop below 40 degrees F for more than a few hours. If your winters are frost-free, you can keep the tree outdoors, protecting it from unusually cool weather by attaching a string of lights to its branches to provide some warmth and moving a potted tree to a spot near a warm, south- or west-facing building wall. If frost occurs where you live, move a potted tree indoors in fall to over-winter until spring.
Provide Abundant Water
Abundant rain falls on the breadfruit tree in its native habitat, and the tree grows best when its soil stays moist and doesn't dry out completely. If the tree is growing in the ground, mulch the area under its canopy well, applying 4 to 6 inches of organic material to retain soil moisture, and water the tree whenever the top inch or two of soil feels dry to the touch. It's a good idea to use drip irrigation or a soaker hose, ensuring soil is moistened to a depth of at least 6 inches. If the tree is in a container, water it whenever the soil surface feels dry, allowing the pot to drain freely. Keeping the tree in a spot where the container is shaded for part of the day also helps slow drying out of its soil.
Pay Attention to Light and Fertilizer
This tree needs direct sun outdoors for about half of each day. If you grow it indoors, pick a spot that's bright and sunny, such as in a window with southern exposure, but protect it from cool drafts during winter. Breadfruit trees usually begin bearing fruit when they're three to five years old and can continue producing for many years, provided they're fertilized to keep fruit coming. Feed a young tree with a balanced fertilizer, such as a 10-10-10 formula, diluted at a rate of 1/4 teaspoon per gallon of water, applied every few weeks during spring and summer. When the tree begins producing fruit, add 4.4 pounds of a granular superphosphate fertilizer to this regimen, applying it once yearly to increase the number and size of fruits, but check product labels for any additional directions when feeding the tree.
Pruning and Problems
An annual pruning helps keep a breadfruit tree vigorous and bearing fruit. Start when the tree's about 4 years old and trim the main, or "leader," stem to encourage branching, wiping the blades with rubbing alcohol between cuts. Continue trimming back side branches each year to encourage bushiness. Mealybugs and soft-bodied scale insects might infest a breadfruit tree, causing young growth to wilt and interfering with fruit production. Control them by spraying the tree with insecticidal soap, diluted at a rate of 6 tablespoons per gallon of water. Spray until the tree is dripping wet and repeat every two weeks as needed. A breadfruit tree might also develop fungal problems such as stem-end rot, which causes young branches to die back and destroys fruits when small. These problems are best controlled by clearing plant debris from under the tree's canopy regularly and, for a container-grown tree, never keeping the tree's pot in a water-filled saucer after rain or watering.