Here you can kind of see the difference between the leaves on the bottom and the leaves on the top.
I've also decided not to plant SO much lettuce next year! 4 squares was WAY too much! We've done our best to eat as much as we can but it just keeps coming back! Another problem was that I tried a mix of red and green leaf salad mix and was not terrifically happy with the results. Some of the lettuce had a bitter, sort of spicy flavor (sort of similar to arugula--which I DO NOT LIKE!!) and we just weren't happy with it. Next year I'm going to stick with romaine and buttercrunch. They're so mild and tender and wonderful so I know I can't go wrong with those.