These fritters are high in flavor but very low in salt.
Toss zucchini and salt in a large mesh colander. Let stand for 10 minutes, then rinse and squeeze to remove as much liquid as possible.
In a large mixing bowl, combine the grated zucchini with remaining ingredients (except for canola oil), and stir to combine into a thick batter, adding more flour as needed. Batter should resemble cream cheese consistency.
Heat about 2 tablespoons of oil in a large skillet over medium heat (add more oil as needed between batches). Drop large spoonfuls of batter into hot oil, flattening gently into think patties. Fry until crisp and golden, about 5 minutes per side. Transfer cooked fritters to a paper towel-lined plate to drain. Serve hot with low-sodium sour cream.