Wash zucchini, retaining peel and removing ends; quarter lengthwise; cut quarters in half. Layer zucchini and salt in a large glass, stainless steel or enamel bowl; let stand 1 hour.

Fill boiling water canner with water. Place 4 clean pint mason jars in canner over high heat.

Place snap lids in boiling water; boil 5 min to soften sealing compound.

In stainless steel or enamel saucepan, combine vinegar, sugar, celery and dill seeds; bring to a boil.

Rinse zucchini in cold water; drain thoroughly, pat dry. Add zucchini and onion to pickling liquid; bring to a boil; boil 5 min.

Place 1 clove garlic and 1 large sprig of dill weed in a hot jar; pack zucchini and onion slices snugly in jar to within 3/4 inch of top rim. Add boiling pickling liquid to cover vegetables to within 1/2 inch of top rim. Remove air bubbles by sliding rubber spatula between glass and food; readjust head space to 1/2 inch. Wipe jar rim removing any stickiness. Center Snap Lid on jar; apply screw band just until fingertip tight. Place jar in canner. Repeat for remaining vegetable and pickling liquid.

Cover canner; return water to a boil; process 10 min for pint jars at altitudes up to 1000 ft. Remove jars. Cool 24 hours. Check jar seals. (Sealed lids curve downward.) Remove screw bands. Wipe jars, label and store in a cool, dark place.