Given the nature of square foot gardening, growing different plants in very close proximity to each other I thought this article was helpful.
Michigan State University Extension
Through the years gardeners have observed that some plants
grow well together, while others do not. This list presents
traditional companions (plants that have compatible growth
habits and share space well), allies (plants that enhance growth
and ward off insects), and enemies (plants that deter good
growth). As you plan the garden, try some of the beneficial
pairings and see if they bring you good results.