Cut zucchini/summer squash lengthwise ¼ inches thick. Brush with 1 tablespoon olive oil, season with salt and pepper, and grill over medium-high until charred and just tender, 3 minutes per side. Toss asparagus with 1 teaspoon olive oil and grill, turning occasionally, until just tender; transfer to a board and cut into pieces.
Split ciabatta bread and grill until toasted, 1 minute per side, then rub each cut side with 1 large clove garlic and brush with 1 tablespoon olive oil.
Spread ricotta on each half, then top with zucchini/summer squash, and asparagus. Zest lemon on top and drizzle with 1 tablespoon olive oil.