March - May
April - July
June - September
If you want to harvest your iceberg lettuce early, you can pre-cultivate your seeds for 3-4 before replanting outside.
Cultivate iceberg lettuce early in the year; you can sow the seeds outside as soon as the soil can be used. Water the soil before sowing and make sure the temperature does not exceed 20°C since this will have a negative effect on the growth. Lastly, harvest your lettuce as the leaves grow bigger, in order to avoid the soil getting too crowded.