I've just grown my first maincrop potatoes - maris peer and a purple skinned one (can't remember what it's called). When I went into the garden this morning the leaves were rotted on all of them. They were fine earlier in the week (a bit chewed by the snails which are plaguing me this summer), and this seems to have happened very suddenly. Like many areas, we've had almost constant rain this summer in Wales. I dug up one plant of each variety. The potatoes are fine, but very small. Should I dig up the whole crop now, or might they grow a bit more if I leave them in the ground?