Persimmon is the fount of vitamins. (?)

Uly, you don't say fount or you do?

Хурма упакована винаминами)) Мне очень нравится!))

Grumbler: PersimmonS ARE A goldmine of vitamins. (a sharon fruit is a very sour variety of persimmon)

исправил
In UK, I think, both are used interchangeably, but BBC says "Sharon fruit is the trade name of a variety of persimmon grown in Israel. It is a ‘non-astringent’ variety of persimmon but still has a tannic taste."

Persimmon is the general, generic name for the fruit.

British English: https://books.google.com/ngrams/graph?content=persimmon%2C+sharon+fruit&year_start=1800&year_end=2019&corpus=29&smoothing=3&direct_url=t1%3B%2Cpersimmon%3B%2Cc0%3B.t1%3B%2Csharon%20fruit%3B%2Cc0

Valery: Persimmons are a storehouse of vitamins.

(1) PERSIMMON без артикля не звучит; (2) существительное, использованное в качестве прилагательного никогда не может быть в множественном числе, так что vitamins здесь неправильно.

А с HOUSES неправильно

*a storehouse of vitamins

"Will NYC's college building boom bubble pop?" — нормально, так как ‘S, это артикль (determiner/article). “Persimmons are a vitamin storehouse” тоже можно, но не самый естественный вариант: https://books.google.com/ngrams/graph?content=a+vitamin+storehouse%2C+a+storehouse+of+vitamins&year_start=1800&year_end=2019&corpus=26&smoothing=3&direct_url=t1%3B%2Ca%20storehouse%20of%20vitamins%3B%2Cc0