Cook farro according to package directions. Place in a medium sized bowl.
In a large bowl stir together arugula, cucumber, green onions, red onion, tomatoes, feta, dill, mint, parsley, and oregano. NOTE: If you plan on using salad for leftovers, stir arugula into individual salads before serving. The arugula with dressing does not save well.
In a small bowl, stir together olive oil, lemon juice, lemon zest, 1/2 teaspoon kosher salt, and 1/2 teaspoon black pepper. Pour over warm farro and mix well. Taste, and add salt or pepper to taste, if needed.
Pour farro and vinaigrette into bowl with vegetables and mix well. Again, taste, and if needed, add more salt and pepper.