I've just discovered that my copy of 'Sissinghurst: An Unfinished History' has gone missing. What's worse, I had two copies at one stage, and consequently gave one away!
'The Poetics of Gardens' (pictured) also went missing a few years ago, and then after publicly singing its praises and lamenting it loss, Richard Padgett very kindly hunted down two copies - one for himself and one for me. Hence the pic!
I really wish I knew where my original copy of 'Garden Design' by Sylvia Crowe ended up. My uncle, on a trip to London in 1985, spent the day on the tube getting around bookshops to find it for me. After reading it many times, and accessing it continually, I went to grab it about three years ago and couldn't find it. I've since tracked down another copy, but it's not the same.

What garden books have you lost track of?