>>2500526idk if they make a English version of this book but that's about the most complete gardening book you get.
written by Johannes böttner 1895, the 32 edition came out in 1967.
it covers everything from soil to fertilizer to exotic flowers.
i have a reprint of the 1895 version. that is my absolute go to book for gardening. also has recommendations for every vegetable like tomatos which were introduced to German gardening by that writer.