One of the easiest annuals to grow, zinnia flowers bring an explosion of color wherever they go. The show lasts from late spring until the first frost in fall. Butterflies and hummingbirds are attracted to the cheery flowers that bloom in nearly every bright color imaginable. They grow quickly and reliably, making them a great choice for first-time flower growers. Add in their low maintenance requirements and the variety of sizes and shapes, and you can’t lose.