For planting from mid-April you can grow the young plants yourself.
Planting dates from mid-April to early May require a cold frame or small greenhouse for cultivation. Sow late February to mid-March, A maximum of 3g of seed is required per m2 of cultivation area. The seed should be no more than 1 cm deep into the ground. Timely hardening before planting out is crucial.
For plantings from mid-May, propagation can already be carried out on open-air seed beds, which, however, must be somewhat sheltered and sunny. The earliest sowing date is the end of March. Anyone who wants to harvest fresh kohlrabi throughout the summer and until autumn, brings from the end of March at intervals of 14 Days to 3 Weeks an appropriate amount of seed for sowing. The last sowing date for outdoor plantings is the third decade of June. Kohlrabi can also be used very well for autumn use in greenhouses and cold frames. In this case, planting must be done at the end of August, be made at the beginning of September at the latest, which corresponds to a sowing date of the end of July. Autumn varieties for storage must be sown or planted from mid-April to early June, depending on their development time. Can be planted from late May to early July.