By: Charlie Nardozzi
If new growth reaches about one foot a year, the trees have sufficient fertilizer. Too much fertilizer, especially nitrogen, will cause fruit drop. An annual application of 5 to 10 pounds of compost per tree in late winter will keep persimmons growing well.
Persimmon trees are mostly dioecious, meaning individual trees produce either male or female flowers. This means you'll need a separate male pollinator tree for the female tree to produce a crop. Although persimmons can produce fruit parthenocarpically (without pollination), Asian persimmons are less likely to drop fruit and tend to produce larger and more fruit when pollinated. 'Galley' and 'Gosho' are good Asian male pollinator varieties.
If you're growing American varieties, it's also best to have a male pollinator variety. 'Meader' is one of the few American varieties that is known to be self-fruitful, but even its fruits will do better if planted with a male pollinator such as American Male. Asian varieties will not pollinate American varieties, and vice versa.
Prune young trees in winter to a modified central leader system with six to eight widely spaced scaffold branches around the trunk to support future fruit loads. American persimmons tend to sucker heavily, so plan to cut suckers away every year. Once persimmons reach bearing age, little pruning is necessary. Thin fruits to one to two fruits per shoot, choosing the ones with the largest calyx.
Persimmons are ready to harvest from September to December, depending on the variety. Asian fruits hold tightly to the branches, so you may need pruners to remove them.
Harvest nonastringent varieties, such as 'Fuyu', when they're still firm but have full color. Harvest astringent Asian varieties when the skin of the fruit turns translucent and the calyx readily separates. Or leave either kind on the tree to ripen into the winter as long as temperatures don't get below the mid-20s. American persimmons drop off the tree when ripe.
If raccoons, opossums or birds begin to eat the ripening fruit first, pick the astringent varieties when they're just beginning to soften and place them in a plastic bag with a few bananas for 7 to 10 days in a warm room. The ethylene gas given off by the bananas will ripen the persimmons.