In a large bowl, add the blueberries, raspberries, blackberries, sliced strawberries, diced apple, halved green grapes, and mandarin oranges. Drizzle with fresh lemon juice and toss gently.

In a small bowl, whisk together the yogurt, honey, and vanilla extract until smooth. Taste and add more honey if needed.

Pour the dressing over the fruit and stir gently to coat evenly. For a cooler, more refreshing taste, chill the salad for 20 to 30 minutes before serving.