Preheat oven to 375 degrees F. Lightly grease a large baking sheet or line a baking sheet with parchment paper; set aside. In bowl stir together flour, baking powder, soda, and 1/4 teaspoon salt. Cut in butter to resemble coarse crumbs; set aside. In bowl stir together sour cream, egg, granulated sugar, and 1 teaspoon of the peel; add to flour mixture. Combine just until moistened. Stir in apricots and dried plums. Drop dough onto baking sheet. Bake 18 to 20 minutes or until golden and toothpick inserted in center comes out clean. Cool slightly on rack.
For glaze, stir together powdered sugar and 1/2 teaspoon lemon peel. Stir in enough lemon juice to make drizzling consistency; drizzle over scones. If desired, sprinkle with walnuts. Makes 16 to 18 scones.