Japanese persimmon (Diospyros kaki) is an Asian native growing well throughout USDA Hardiness Zones 7 through 9. The deciduous tree is suitable as both a shade or specimen tree, growing up to 30 feet in height. The trees have attractive fall foliage and produce orange-colored fruits that are prized by humans and wildlife. If pests become a problem, gardeners have choices in a variety of pesticides suitable for use on the tree.
Scale is one of the most common pests affecting persimmon trees. Trees are affected by both soft and armored varieties, with white peach scale (Pseudaulacaspis pentagona) being the most common. Scale insects are white and appear in clumps along the plant’s branches and trunk. Insects suck the plant's juices and weaken its growth. Trim infected sections to remove the insects, or spray with a pesticide, summer or dormant horticultural spray. The trees require spraying in two applications applied one to two weeks apart.
Fungus and Borers
Poor growing conditions, planting outside of the trees growing range and stress leads to several problems in a persimmon’s health. Weakened trees are prone to developing the fungus Botrysphaeria dothidia, which leads to metallic woodborer infestation. The fungus, commonly called gummosis, discolors the woody trunk and long, vertical scars form on the bark. The woodborers lay their eggs in the scars on the trunk where they hatch and eat the bark’s inner tissues. Borers are difficult to control. The borer damage weakens the tree and results in loss of limbs. Offering trees proper planting and growing conditions reduces the possibilities of contracting the disease and pest.
Persimmon psylla is an insect that primarily attacks new leaf growth on trees. Leaves affect by the psylla have a crinkled look and are curled and malformed. Pests attack the underside of the tree’s leaves and appear as a white mass. The pest, if not controlled, will stunt new growth on trees, primarily younger ones. Controlling the insect is difficult due to their location on the leaf’s underside. Gardeners should spray with a pesticide aimed at controlling the insects.
Stinkbugs are common insects that only become a problem when the persimmon tree’s fruit begins ripening. They affect only nonastringent varieties. The insects suck juices from areas of the ripening fruit, and their damage shows up as white areas in the fruit’s meat under the skin. Stinkbugs do not damage the tree and are hard to control, as they do not live on the plant but come and go as they please.