Tomato Herbicide Damage from Grass Clippings: Classic Cupping Symptoms

Curling, cupping, strapped tomato leaves = herbicide damage. Your dried grass clippings came from a lawn treated with broadleaf weed killer. Fumes or leachate reached tomatoes. They're hyper-sensitive. Some vines may "grow through" it—watch and see. Fruit safety unknown.

Herbicide damage to tomatoes

Herbicide damage to tomatoes

Grass clippings containing herbicide