Romaine lettuce is another hugely popular lettuce, with leaves that have unparalleled crunchiness. It is most commonly found in salads. Romaine lettuce is quite easy to grow, though it prefers more space than other types of lettuces- making it an excellent choice for those of us lucky to have backyard gardens. Romaine is more heat-tolerant than other types of lettuce, so it can really be planted any time in the season and do well! They enjoy partial shade.