In a strainer, toss the shredded zucchini with the salt and let sit for ten minutes. Then thoroughly squeeze out as much moisture as you can.
In a large bowl, combine the zucchini, ricotta, yogurt, feta, garlic, scallions, dill, eggs, lemon zest and 1 teaspoon each of salt and pepper. Stir well, then stir in the flour just until incorporated.
Line a large baking sheet with paper towels. In a large skillet, heat ¼ inch of oil until shimmering.
Working in batches, add 2-tablespoon mounds of the zucchini batter to the hot oil, spreading them to form 3-inch fritters.
Fry over moderately high heat, turning once, until browned and crisp, about 3 minutes.
Drain the fritters on the paper towels and serve right away, with lemon wedges and a little tzatziki.
