I am about to convert a lunge ring into a garden. It is about 120 feet in circumference. My plan is to divide it into 4 quadrants with a circular path dividing two larger beds, per quarter. The total beds will be 8. I will most likely cover the area with cardboard before putting horse manure on top. I will mulch the paths with bark. I plan on putting potatoes, squash and corn out there, as well as other sprwalers. Any suggestions?