Pulse chop the vegetables in a food processor to save time. Cut the vegetables into one or two-inch chunks then put them in the processor only filling it a single layer at a time. If you put more in at a time, some of the vegetables turn to a purée before it’s all chopped.
Peel cucumbers. Slice in half lengthwise and scrape out seeds with a spoon. Chop into small pieces in food processor and place in a large stainless steel or glass bowl.
Chop remaining vegetables and add to the bowl.
Sprinkle salt over vegetables and stir.
Cover and let stand for four hours.
Drain the vegetables in a large colander and rinse with cold water. Allow the vegetables to continue draining while you prepare the jars and the brine.
To prepare the jars, wash and rinse well. Then place in a canner and fill with water. Add a splash of vinegar to prevent hard water marks on the jars. Boil jars for ten minutes to sterilize.
Bring vinegar and sugar to a boil in a large stockpot. Boil for two minutes to dissolve sugar. Add celery seeds and mustard seeds.
Add vegetables to the stockpot. Return to a boil then reduce heat and gently boil for 10 minutes.
Pour relish into hot, sterilized jars to within 1/2-inch from the top. Wipe rims clean.
Apply hot snap lids and secure with a ring. Screw on rings to finger tight.
Process in a boiling hot water bath for 10 minutes, or for the recommended processing time if you live more than 2000 feet above sea level.
Carefully remove the jars from the canner and place on a heat-resistant surface.
Listen for the snap! That means the jars have sealed and they are safe for storing.
Allow relish to cool for 24 hours before transferring to your pantry.