As seen in The Daily News July 10 2009
Q: I have a “Fuyu”and a “Hachiya” persimmon. Both set heavily this spring, and now both are dropping fruit heavily.
Weather has been in the 90s the last two days, but dropping started before the hot spell. They’re dropping dozens every day! Could I not be watering enough? Can you suggest anything that might stop the drop? Also, how should they be watered? Frequent or sparingly?
(2800 feet elevation)
A: To answer this question, I turned to Alex Silber, proprietor of Papaya Tree Nursery in Granada Hills (email@example.com). Silber grows and sells more than 150 types of fruit trees, most of them exotic and rarely seen in Los Angeles.
He writes: The Japanese persimmon is a relatively forgiving fruit tree as it grows in various soil types, as long as drainage is good, and over a wide soil pH range. Even though the persimmon tree is considered relatively drought tolerant (once established), it can also tolerate heavy watering as long as the soil drains well. Other than poorly drained soil, another common cause of fruit drop is inconsistent watering practices.
Irrigate once or twice a week beginning in spring and throughout the growing season.
The persimmon has a tendency to bear fruit every other year (biennially) and that can be controlled by proper fruit thinning just after annual fruit drop in June. A lighter, but more stable, crop is also achieved by proper pruning in December and again lightly in summer. The idea is to remove branches that are too close to each other for a more evenly dispersed branching structure, which will in turn reduce the fruit load. Fruit is borne on current season’s growth as well as on some one-year old wood. In addition to thinning cuts, heading back the tree to a manageable height is also recommended, especially in the top center of the tree.
Remove almost all twiggy growth, favoring the thicker diameter wood which has more potential to produce a decent quality fruit.