carole's, advice is good if you only want new potatoes. For larger potatoes, they should be left at least until the foilage has died back... they will continue to grow larger even after that...
depends on which you planted. First earlies may be ready now,second earlies in a couple of weeks,main crop from about mid-august onwards Scrape the soil from round one and see what you think. Don't forget.longer they remain in ground,more feast the slugs will have
I watch mine and if any go yellow or get patches of blight I get them first.
If they've got blight chop off the leaves and burn them without letting them touch the soil or potatoes, especially if you want to store them
We have started on ours. Even if they are small they are nice (and shop new spuds are dear early on, but the old ones don't taste right now). Just dig one root at a time then the rest can go on growing.
When you lift the plants, take off the big ones & leave the little marble sized ones.
Cut off two thirds of the old haulm, replant and you will have new potatoes on Christmas Day. You can plant 3 plants where one old one went, so you'll get most of your plot back too.
This really works!