Plants from all over the world flourish at Tresco Abbey Gardens, thanks to the unusually warm climate Tom Parker A flicker of wings catches my eye, darting through the small churchyard before alighting on a lichen-laced tombstone, a distinctive red tail bobbing up and down. This delicate black redstart has recently arrived from Eastern Europe – here, like so many unexpected plants and animals on this exotic archipelago, for the mild climate. I am on Tresco, the second biggest of the low-lying granite islands that make up the Isles of Scilly – cast like rose petals into the Atlantic, off...