This year I planted my lettuce from seeds, plenty early. You can see in this picture the tiny starts where I planted more seeds to get a second crop.
I also learned from my mistakes and put the containers up high and out of the reach of pesky bunnies. Last year my entire crop of lettuce was devoured in one night by some apparently ravenous rabbits
This size container worked perfect. They got plenty of sun and rain sitting out in front of my house.
Sorry bunnies, no lettuce for you!