What are the easiest types of lettuces to grow in Missouri?
There are four types of lettuce: crisphead, butterhead, leaf, and romaine. Head lettuce requires a relatively long growing season and will turn bitter or bolt if temperatures in late spring are very high. So, I would not recommend trying to grow it in Missouri. Leaf, butterhead, and romaine can withstand greater fluctuations in the environment and have a shorter growing season.