Substitute plain thyme or thyme with a pinch of sage or mint for summer savory. Thyme is a bit stronger than summer savory, but is still in the same flavor family.
Summer savory has a mild flavor that pairs well with meat, fish and beans. Its mild flavor also works well in egg dishes and stands up to the long cooking times required for stews and casseroles. Winter savory has a stronger flavor and tougher leaves than summer savory. It is necessary to use a smaller amount of winter savory when choosing it as a substitute for summer savory. It is an especially good substitute in stews and soups that have long cooking times.