We need to mound up the Potatoes now, they are at a good size, we take a rotavator between the rows and break up the soil, this soil is used to mound up the rows, it is also a good way to sort out the weed problem, if you mound them up enough you will only have to do it the once, and this should be the only time you have to knock down the week because the leaf spread should stop any more coming through. The problem now to watch out for is blight. 
Great Dixter Vegetable Garden 