This is a MUST READ for anyone growing tomatoes. There's LOTS of science behind this planting plan that makes super healthy plants. Links give even more advice/ with pictures. -awesome article on tomato growing
plumbago (Ceratostigma plumbaginoides, zones 5 to plant grows well in sun and part shade in all kinds of conditions all over the U. It chokes out weeds, blooms in a clear blue that reflects the summer sky and tops it off with fantastic fall color.