Zinnias grow to between 15 and 100 centimeters in height. They have single and double blossoms which are varying in diameter from 3 to 15 centimeters. Zinnias form bushy, erect, self-branching plants. The petals can be any of a wide compass of colors or multicolored. The ray petals of the flowers may be quilled or flat and they come in every shade except blue. Picking off the dead flowers will increase the blooms.

A flower, also known as a bloom or blossom, is the reproductive structure found in flowering plants (plants of the division Magnoliophyta, also called sperms). The flower structure contains the plant's organs, and its function is to produce seeds through reproduction. For the higher plants, seeds are the next generation, and serve as the primary means by which individuals of a species are dispersed across the landscape. After fertilization, portions of the flower develop into a fruit containing the seeds.