Combine first 7 ingredients in large pot. Bring to boil. Reduce heat and simmer 10 minutes to blend flavors. Strain liquid into bowl; return to same pot. Discard solids in strainer. Bring liquid in pot to boil. Add squash; reduce heat and simmer until squash are crisp-tender, about 7 minutes. Stir in lemon juice. (Can be made 6 hours ahead. Cover and chill. Rewarm over medium heat, if desired.) Stir in parsley. Serve soup hot or chilled.