Preheat grill to medium-high heat. Rub 1 tablespoon of oil over the corn.
Grill corn for 15–20 minutes, turning occasionally, until lightly charred.
While the corn cooks, prepare all other ingredients.
In a small bowl, whisk together lime juice, remaining oil, salt, and pepper.
Let the 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 and gently toss.
Serve immediately for the best flavor of this Grilled Corn Salad with Blackberries.