Medium sized, healthy potato tubers of pronounced early varieties are the best for laying.
The sprouting and root formation after the potatoes are laid are at the expense of the reserve substances stored in the tubers. Small tubers have too few reserves, to get a strong shoot, which is the prerequisite for early harvests. On two 6 m long normal beds are required at least 80 The potato tuber (so-called seed potatoes). For quite large ones you need considerable space for pre-germination. That is why the medium-sized tubers are used for early cultivation, who have sufficient reserves.