At a moment when the planet is so clearly in peril, the trees stand as both guardians and messengers. They have words for us – if only we would listen. As climate change imposes significant challenges on the natural world we are being encouraged to plant trees. At the same time, urban intensification and expansion threatens our existing arboreal resources and leads to disputes among communities, councils and developers over the fate of mature trees. To find our way through this confusion, we need to build our respect for trees and to recognise their essential role in our environment, our heritage, our well-being and our future. We need to build a robust ‘tree sense’.