Zinnias! Zinnias are one of my favorite flowers because they bloom in late summer and all through September. Also they are very easy to grow. Back in May or June, I opened a packet of zinnia seeds and sprinkled them into the ground in a spasticated fashion, then watered the area daily, and now they are about 3 feet tall! I love that they are so bright and cheery and they look like cartoon flowers.
This batch of seeds produced mainly deep fuschia flowers
But here's a lone light red one!