The pre-germinated new potatoes must not be laid before mid-April.
Potatoes are very sensitive to frost. This is especially true of the developing shoots. They also need to drive- and root formation much heat, which is not present before mid-April even in humus-rich sandy soils. Therefore it is at unfavorable, better in wet and cold weather, leaving the pre-germinated potatoes in the pre-germination boxes for a week longer.