Any opinions of this: I planted a type of red leaf lettuce in a container last summer and it grew well. I added it to my salads all summer. In the fall I emptied the container and discarded the plant. Today I was working on my garden and I noticed that in the crack between my patio stones and the house, right where the container with the lettuce grew last year, there is a plant growing that appears to be the lettuce! Does lettuce reseed or could a root have grown out of the bottom of the container and survived all winter?