In Dave's article he states "grow corn, beans and squash together. The corn feeds on the beans' nitrogen while providing climbing support to the beans. The squash provide a thick groundcover that preserves moisture while blocking weed growth."
David, I would just like to add: Climbing beans can indeed be grown with corn, and squash, BUT: this works best with a corn that is being grown for mature, dry ears -- such as popcorn, ornamental corn, or corn intended to be ground into cornmeal, and with a bean variety that is a "weak climber" that will not overwhelm the corn, and is being grown to obtain dry beans, such as soup beans (not snap beans). That way, when the squash is mature and ready to harvest, the corn and beans are also ready; trying to harvest sweet corn and/or snap beans from a patch filled with squash vines is a near impossibility -- I tried it in my (much, much) younger days and speak from experience!
