just wondering how high up the stems do i earth and do i do it just once or a few times. first time growing spuds and want to get it right.
Normally is is enough to do it once. But if the potatoes were planted on the flat, that is not in raised drills, it might need to be done twice, again depending on how much soil is thrown up.
Decide on the basis of whether small tubers are showing at the surface or close to it. This can be done by rubbing away the soil surface with your hand and if the tubers are pushing close, then they will push out as they grow and turn green, which renders them inedible.