Wann kann umgetopft werden von 4 auf 11 L Töpfe?

You can transplant any time you want. Putting plants in small pots is mainly done to conserve space. Many people transplant with the plant fully grows to the edges of the pot. If you do not need to save space go right for their final pot size. I sow my seeds directly into their forever pot. That way there is no transplant shock which stresses plants and can add a few days to the grow period.