Plants, whether in a lawn, garden or landscape are just that, an investment. In order to get the most out of that investment, you have to know what is needed to sustain it. The soil is the foundation which supports your investment so it only makes sense to know and understand what, both scientifically and biologically, is required to enhance that foundation. To answer this I would need to know what part of the Midwest you are referring to, such as, Chicago, St. Louis or Dallas. The choices in sun tolerant perennials is quite extensive, however all plants are rated by their tolerance to cold according to the USDA hardiness zones 1-10.
Soils are different in all parts of the country as well.
Many plants will survive in a sandy soil and many require a moist, but well drained loamy soil. Once you have determined your zone, decide what color or leaf texture you like then select a perennial that will not only tolerate, but perform in that exposure. The same plant in my yard has died every year for the last two years. Landscaping mistakes can be very expensive and frustrating. As mentioned above, determine that the plant you have will actually grow in your climate.