A book has a genre and sometimes it can be classified as being in more than one, or occasionally none.
I am writing a historical novel and there's romance in it when Durstan, my Monk, falls in love. The novel also deals with the effect of religion on society in 794AD.
I have plots in mind for later books which will again fit the historical romance genre but, apart from the sequel to Durstan's tale, are likely to be set in different centuries.
I enjoy reading books from many genres, including ghost stories. Halloween is a great time for these when I'm in the mood to be afraid.
There are plenty of poetry and gardening books on my bookshelves. The occasional Chick Lit novel too with it's inevitable happy ending.
I have a few Victorian and early 20th century gardening books. I've enjoyed reading about the travels of the plant collectors in the 1800s, the traditional organic methods used, the great gardens like Kew and more recently the Eden Project in Cornwall.