If there is danger of frost at night, the shoots above the ground must be covered with soil

If there is danger of frost at night, the shoots above the ground must be covered with soil.

Even the slightest night frost destroys the potato shoots, that protrude from the earth. This completely calls the early harvest into question. The best protection against such setbacks is piling up earth. Only so much soil is used, that the potato sprouts including the leaves are no longer visible.