An Oriental or Japanese persimmon tree (Diospyros kaki) can grow 30 feet tall and 25 to 35 feet wide over many years, as it tends to grow moderately slowly. Pruning trees can limit height, making fruit harvest easier in the backyard orchard. It also trains the young tree into a wide, open structure for the best fruit production later in life. Cultivar Fuyu, also known as Fuyugaki, grows up to 20 feet tall and 22 feet wide. It produces baseball-sized, tomato-shaped orange fruits that are naturally sweet -- nonastringent -- and have a flavor reminiscent of a cantaloupe. Harvest time is in middle to late fall.
When buying a Fuyu persimmon tree at the plant nursery, look for plants that are vigorous and healthy in their containers. Choose a tree with three to four wide-angled scaffold branches. Once planted, do not be quick to conduct any pruning on the young tree, as the first year may produce little new leafy branch growth or fruits because the root system is establishing. Keep the soil evenly moist year-round as long as the soil is not frozen. A well-established persimmon tree after the first one to two years after planting performs better and bears fruits earlier compared to trees neglected after planting.
During the first five years after planting the Fuyu persimmon, evaluate the branching structure and appearance of new growth. In the late winter after the first full year after planting, when the tree is still dormant, prune away all branches from the trunk that are not the original three or four scaffold branches first seen at the nursery. This includes any upright, vigorous shoots -- called watersprouts -- that jet up from the main scaffolds. Removing these watersprouts increases air and light penetration into the persimmon tree, keeping it healthier and promoting more branching growth.
In the second year after planting, again in late winter, remove all watersprouts from the Fuyu persimmon's canopy. Also remove any branches that grow inward into the center of the tree. Cut back all scaffold branches to a length of 36 inches from the tree trunk. This will cause side branching over the summer. The basic structure of the persimmon tree is now formed for future years.
Rather than letting the Fuyu persimmon reach its mature height of 20 feet, maintain it by pruning it back every late winter to a height of about 8 feet. For the rest of the tree's life, the annual pruning maintenance includes pruning out dead branches, all watersprouts and all inward-growing twigs and branches. Cut back the tops or tips of branches to shape the tree. Use a method called "mold and fold," which is cutting back branch tips into 2-year-old wood. Make the pruning cut 1/2 inch above an outward-growing lower branch. This tip pruning keeps the tree productive with lots of air and sunlight penetration through the canopy, as well as a shorter tree that is easier to harvest, even with a standard A-frame ladder. Over decades, the Fuyu persimmon is pruned back to around 8 to 10 feet tall, but the canopy progressively widens to approach its natural width near 15 to 20 feet.
For branches and twigs less than 3/4 inch in diameter, use a sharp-bladed hand or bypass pruners. Loppers are best used on branches 3/4 to 1 1/2 inches thick. Anything larger should be cut with a pruning saw.