Asian persimmon trees are becoming popular additions to American gardens across the country. Their sweet yellow-orange fruit and the handsome tree shape make them attractive additions in backyards and as focal points in front gardens. Persimmons, like many fruit trees, are susceptible to attack by several insect species that can damage its roots, leaves, trunk and fruit. There are organic pesticides that can both eradicate and deter insect infestations.
Persimmon leaves are susceptible to a soft-bodied insect called the Persimmon Psylla. This insect feeds on the trees immature leaves. Damage can be identified by curled and misshapen leaves that do not have the same sheen as regular leaves. Soap-based insecticides like Safer's soap can be sprayed directly on the insects to kill them. The spray must be applied to every part of the tree where the insects might be hiding, including the underside of the leaves. Another application can occur a week later if there are still signs of the insects around. Adding 1 tbsp. of dish soap to 1 qt. of water, mixed thoroughly and applied with a spray bottle can make an inexpensive insecticidal soap.
Dormant or Summer Oil
Spraying a dormant or summer oil on certain insects suffocates them or penetrates through their shell to disrupt cellular activity that kills them. Both dormant and summer oils can be derived from petroleum or from cottonseed, depending on the manufacturer. Dormant oil is formulated for application before the persimmon's leaf buds break and is a heavier oil than summer oil. Summer oil can be applied during the growing season. Persimmons can be attacked by several varieties of scale including white peach scale. These types of scale are best controlled with an application of dormant or summer oil in spray form. A second application can be made in one to two weeks if scale still appears to be a problem.
Nematodes are tiny parasites that attack many harmful insects in their larval stages. Persimmon roots can become infected with clearwing borers that chew into the roots and decimate the tree over time. Beneficial nematodes are pest-specific, there are different nematodes for different pest problems. Make sure that the one you purchase will attack clearwing borers. Two species of nematodes that are particularly effective against the clearwing borer are Steinernema carpocapsae and Steinernema feltiae. Nematodes should be used quickly after purchase, as they are living creatures.