In a large pot combine 8 cups water, the farro, and quinoa. Add 1 tsp. of the salt to the water and bring to a boil. Reduce heat and simmer, covered, for 15 minutes or until both grains are tender, adding the edamame during the last 6 minutes of cooking. Drain and rinse under cold water. Set aside.
In a large bowl whisk together the lemon juice, olive oil, remaining 1/2 tsp. salt, and pepper. Add the arugula, cooked farro, quinoa, and edamame to the bowl and mix well. Transfer to a serving container and top with the feta, dried cherries, and blueberries. Serve at room temperature.