Combine the chopped vegetables in a large nonreactive kettle or bowl.
Add the salt and stir to combine thoroughly. Cover and let stand for 4 hours or refrigerate overnight.
Drain the vegetables and rinse thoroughly.
In a large nonreactive stockpot bring the vinegar, brown sugar, and seeds and spices to a boil.
Reduce heat to medium low and continue simmering for 5 minutes.
Add the drained vegetables and bring back to a boil.
Reduce heat to medium low and simmer for 10 minutes.
With a slotted spoon, pack the vegetables into prepared jars. Cover vegetables with the pickling liquid, leaving about 1/4-inch headspace. With a clean dampened cloth, wipe the rims of the jars. Place the flat lids on the jars then close caps with screw-on rings tightly, but do not over-tighten. Arrange the filled jars in the canner and add more water, as needed, to be at least 1 inch above the jars. Bring to a full boil. Cover and continue boiling for 10 minutes. Remove the relish to a rack to cool completely.