digging up potatoes

i grew some potatoes in pots and one of them was kept in my greenhouse so the plants are a lot bigger than others and had been like that for a few weeks do you reckon i could a few early pototoes or should i leave them ( first earlies arron pilot)

thanks

when did you plant them? 

I planted them on the 12th of march

I typed up an answer to this earlier .....but it's obviously lost in the ether  so I'll do it again............

Lay the pot on it's side and ease the filling out a bit to see what's formed underneath. If it's too early just ease it all back inside and the plant will carry on growing.