Wash the salad greens, let drain and refrigerate.
Cut the turkey into 1/2-inch pieces to measure 2 cups. Thinly slice the celery to measure 1 cup. Peel and cut the green onion into 1/8-inch slices. Drain the orange segments and water chestnuts in a strainer.
In a large bowl, mix the yogurt and ginger. Stir in the turkey, celery, onion, orange segments, water chestnuts and grapes. Cover with plastic wrap; refrigerate at least 2 hours.
On 4 plates, arrange the salad greens. Top greens with turkey salad.