When I made the plan for this year, I tried to sneak a square of lettuce between the three pea plants. The thought on this was to spread the peas apart and give them more room on the trellis. Good in theory. In reality, the trellis got in the way of the lettuce plants and the peas enveloped them so they basically quit growing. Next year, the spots underneath the trellises are for plants that need them.