1st early potatoes are usually ready 12 weeks after planting. Try moving the soil aside to see if you can spot any reasonable size tubers.

With earlies the foliage often dies down soon after they flower and they won't make much more growth then anyway. But as Moon grower says, if you carefully dig around one or two plants with your hands, you can see if the tubers are large enough to harvest.
With lates, you need to leave them as long as possible to get a good size potato and maximum crop. Some varieties, like Pink Fir Apple, need to be left right until September unless the blight gets them first.

I love Pink Fir Apple potatoes - even though they are fiddly. Another potato I really like is Anya.

I love pink fir apple too but only when young - they go floury if left in too long and we prefer them creamy!
Agreeanout Anya too - lovely.
I have got blight for the first time this year so all the tops are off.

Sorry to hear that Stera. we are still okay right now and should be able to start lifting 1st early tatties very soon.

I like pink fir apple when young too, I just scrub them as well as I can to clean, leaving skins on - Yum!!

Bulba and I are going to take a look at our first early potatoes tomorrow - if it isn't raining!