Unknown to many, the difference between summer squash and winter squash is simply related to the time of harvest. Summer squash are picked early while immature and the shells are still tender. Winter squash are taken up later in the season with the traditional autumn harvest once their shells have hardened up—making their way into grocery stores and fall harvest festivals everywhere. Each have plenty of uses and are fantastically nutritious. However, summer squash is the handiest for summer soup-making, which we will be working with for today's recipes of summer squash soup.