LORELAI: Hey, why isn’t Jackson here?
SOOKIE: Oh, he’s singing to his persimmons tonight. They’ve been a little sour lately.
Persimmons are the edible fruit of a number of species of tree in the genus Diopyros. Technically the fruit is a berry, although not often thought of that way. The most commonly cultivated is the Oriental persimmon (Diospyros kaki) – one of the most commonly human-grown fruit trees on Earth, and first cultivated in China more than 2000 years ago, then spread to Japan and Korea in the Middle Ages. It was introduced to southern Europe and California in the 1800s.
Jackson may be growing American persimmons (Diospyros virginiana) [pictured], native to the eastern states of the US, and very hardy in cold weather. They’re harvested in the fall, and eaten fresh or used in baked goods and steamed puddings. Jackson’s persimmons are months away from harvest, so no wonder they are sour! The fruit is very astringent or even bitter unless it is fully ripened.
The previous year, Jackson danced to his watermelons and threw his back out.
The Annotated Gilmore Girls 