The more you earth them up the more spds you get, so if you earth them up so there are no green bits showing, then let them grow through and earth up again. So it really depends on the growth reate of your spuds, Mew!
there are so many different opinions on this one we went with advice from RHS - earth up when the green plants get to 9inches - just the once.... but we are new to spud growing.
Red
I like like minded people... a bit like minded anyway.. well people with bits of their minds that are like the bits of my mind that I like...
I would go along with Nev. If the plants are allowed to get too high and you earth them up you could be knocking them back a little each time. By just allowing them to poke through and then earth up, they haven't got such a struggle.
Robin
'You know you are a hard-core gardener if you deadhead flowers in other people's gardens.
To err is human. To blame someone else, is management potential.