Zinnias are one of the easiest annuals to grow, grow quickly, and bloom heavily. They make a massive burst of color in your garden.  Zinnias have bright, solitary, daisy-like flowerheads on a single, erect stem.  Plant them in full sun.  Zinnias are adaptable but prefer fertile, humus-rich, well drained soil.  If the soil is amended with compost, the flowers will grow more quickly.  Deadhead to prolong flowering. Maintain moderate soil moisture and fertilize lightly.