Shirley Poppy (Papaver rhoeas) offers large, bright-red blooms that are perfect for adding a bold pop of color to your gardenscape. In the Northern half of the United States, you’ll want to sprinkle these wildflower seeds in the spring, but if you live in one of the Southern states, you can sow in the fall. These annuals can handle full sun or partial shade and grow 2 ft. tall by 1 ft. wide.