Lettuce grows best in full sun, though excessive heat can cause plants to bolt to seed, or leaves to wilt.
Tip: South African full sun, especially during summer, is generally too hot for lettuce production and they should be grown under shade - 30 to 40% shade cloth would be ideal or within the semishade of trees.
Lettuce is a great plant for beginners! It's easy to grow and you can get different varieties depending on your preference. Lettuce bolting usually happens in the hottest months of South African summer when it does poorly under excessive heat exposure (January - February) - so provide some shade or Research shows most types do better with minimal sun exposure during these hot spell times since they're generally shorter day-length plants anyway.