Analyze the location in which the garden will be. Note whether the garden will be in full sun, full shade, partial sun or partial shade. Different types of summer plants will thrive better in full or partial sun and some will thrive best in full or partial shade.
Think about the type of climate the summer plants will reside in. Some summer plants will thrive better than others, depending upon the garden's location. Some types love extreme heat and others won't be able to survive.
Determine how much color you want in the garden. Do you want a lot of color? Do you want flowering plants? Do you want lots of green or many different colors?
Choose flowers and summer plants that will thrive in the climate and location that your garden will be in. Begonias, Calibrachoas, Fuchsias and Annual Black-Eyed Susans are great picks for annual summer flowers.