Zinnia linearis This variety is the ancestral zinnia type discovered by Spanish explorers in southern Mexico in 1789. Zinnias were brought back to Europe and quickly became a favorite flower. Classic Zinnias reach just 12-14 inches tall and produce lots of 2 inch blooms in a bright mix of colors. Will flower continuously throughout the second half of summer.. Full sun. Annual.12-14 inches. 25+ seeds.