Sowing

Sow thinly about 0.5 cm deep! The seeds need light and a temperature below 18oC to germinate. A higher temperature causes late and bad germination. Lettuce can be forced very early in a green-house (soil temperature at least 5°C) or sown indoors and in hotbeds 3-5 weeks before handle several degrees of frost. Direct sowing can take place as soon as the soil is ready. Water the row before sowing if the soil is dry. That lowers the temperature some when sowing in high summer. To get a supply of lettuce all through summer and autumn, sow successively or several kinds of different growth times! Autumn sowing for wintering could succeed. 

Spacing

Thin out early! Batavia lettuce need a mutual space of 20-30 cm to be able to form heads, 35-50 cm between the rows.  

Harvest

The lettuce heads should be harvested as soon as they have made heads.

Seed

700-1100 seeds/g, a normal portion sows 5-10 m outdoors or yields 100-250 seedlings for setting and 5 g for 100 m if sowing directly and 20 g yield seedlings for 1000 m2. 50-100 g sows 1000 m2 directly.
A portion contains about 70 seeds.