Something is wrong with my lettuce
Something is wrong with my lettuce. I have lettuce growing in two beds in my garden and in some containers. They all have this problem of sunk in areas.
Some are direct seeded, some are sown indoors and transplanted. I have 10 different varieties of lettuce and they all have the problem. Earlier this year I ripped out all the lettuce in the yard, waited a few weeks and resowed. They all have it again.
They can be view at this link: http://www.smugmug.com/gallery/23765486_fhjH8Z#!i=1924972229&k=v99xZ7W
Or the pics below. Any Ideas???