Planting to avoid weeding

I can't believe how much the lettuce has grown.  The lettuce bed seemed to go from small little plants to full lush lettuces overnight.  I love the look of the lettuce, and one of my favorite parts of the lettuce bed is that I haven't had to weed it--not even once.  There are a couple weeds here and there, but nothing like some of my other beds.

When I planted out the lettuces, I was careful to give them room to grow, but I planted them as close as possible (roughly 6" spacing).  This allowed me to plant a large number of plants in a small area, and the spacing allowed the leaves and roots of the plants to out-compete weeds. This also means that as I start harvesting the lettuce, I'll be giving the remaining lettuce a little extra room to spread out.