Sow the Batavia seeds directly into the soil, once it is dry enough to cultivate. The seeds will not germinate until the soil reaches an average temperature of more than 40 degrees Fahrenheit.
Seed the rows 12 inches apart, to allow the plants room to grow large heads. As the lettuces grow to thumb size, thin them to a 10- to 12-inch spacing between plants.
Ensure that lettuces receive full sun for at least part of the day and good light for the remainder.
Feed the lettuce beds regularly with good mulch, well-aged manure or a nitrogen-heavy fertilizer.
Harvest your lettuce once you feel the size of the head is adequate. The best time is in the early morning, after the dew has evaporated but while the soil and the lettuce are still cool.