Sprinkle salt over vegetables and mix thoroughly; let stand 3 to 4 hours. Drain; rinse and drain thoroughly. Combine sugar, spices, horseradish and vinegar; simmer 15 minutes. Add vegetables and bring to a boil. Pack hot relish into hot jars, leaving 1/4-inch headspace. Adjust two-piece caps. Process 10 minutes in a boiling-water canner.