Preheat a grill to medium-high heat. Brush the corn with 1 tablespoon of oil.
Grill corn for 15–20 minutes, turning occasionally until lightly charred and tender.
While the corn cooks, prepare all other ingredients.
In a small bowl, whisk together lime juice, remaining oil, salt, and pepper.
Let grilled corn cool slightly, then cut kernels off the cob.
In a large bowl, combine arugula, radishes, blackberries, avocado, green onions, and corn.
Drizzle dressing over the salad just before serving and toss gently.
This Grilled Corn Salad with Blackberries is best served fresh for maximum flavor and texture.