<p>What is the best way to kill weeds in paving? How scared should we really be of Japanese knotweed? And what is a weed anyway?<br><br>Biologist Ken Thompson set out to write a different kind of gardening column, one that tackles what he calls 'the grit in the gardening oyster'. In this new collection he takes a look at some of the questions faced by gardeners everywhere in a bid to sort the truth from the wishful thinking.<br><br>Why ...