Another topic from the Blogtabulous VP - not so sure about it myself - if you start recommending things just because they have a smidgen of gardening in, sooner, or later someone will recommend that awful TV detective thing with Felicity Kendall in.
How about non-gardening books that still have interest for us as there is at least a little bit of gardening content in them?
My starter for 10 is 'O Beloved Kids' by Rudyard Kipling. It's a collection of his letters to his children - I came across extracts whilst going through the Batemans garden archive at the National Trust. The letters themselves are lovely, but there's also reference to what's been happening in the garden (hence the extracts in the archive) and dates from around the time that Kipling wrote 'The Glory of the Garden'. It's also extremely poignant as not long afterwards his son John went off to fight in WW1.
It's one for the second hand or library search, though Emma will be relieved to find that prices should be a bit more reasonable on Amazon this time.