Finely shred potatoes. Soak potatoes in cold water to remove starch. (A flour sack towel works well for this- place towel in a bowl with edges hanging over the sides. Put the potatoes in the bowl and cover them with cold water.) After 10-15 minutes squeeze out potatoes, rinse bowl, and repeat the soaking process one or two more times as needed to remove all the "pink," or "white" starch which sinks to the bottom of the bowl.
While potatoes are soaking finely chop the parsley, and finely shred the zucchini and onion. Put onion and zucchini in a colander to drain off excess juice. You can carefully press out even more juice. The key to the success of these latkes is washing the starch from the potatoes and removing any excess liquid from the vegetables.
After the final soak, squeeze out as much water as possible from the potatoes. If using a towel, then twist the top of the towel continuously, squeezing the potatoes into a ball, and wringing out all the fluid. Combine potatoes, zucchini, onion, parsley, salt, herb seasoning, eggs and flour in a large bowl and mix well.
Heat oil in a medium skillet until the surface is shimmering. Add large spoonfuls of latke batter to the oil and shape them into pancakes about 1/4 inch thick. Fry until golden brown (approximately 6 minutes each side).