Zinnias vs. Marigolds

Size

• According to West Virginia University Extension, zinnias range from 12 and 36 inches high. Zinnias need 6 to 18 inches of space between flowers. The final height of the flowers determines the amount of spacing because dwarf varieties need less space than taller zinnias. Marigolds range from 6 to 48 inches tall and will spread between 6 and 36 inches, proportionate to height.

Genuses

• Zinnias and marigolds, are related, but not directly. They both fall into the plant family Compositae, but the zinnia and marigold are under different genuses. The zinnia belongs to the genus zinnia, as seen in the Latin name for its various types. Marigolds belong to the tagetes genus.

Colors

• If you want the widest range of colors possible, choose zinnias. These flowers are available in every color of the rainbow, with the exception of blue. As the name suggests, marigolds come in shades of gold or orange with some red and burgundy varieties available. Striped varieties of marigolds add an unusual look to the landscape.

Leaves

• If you are not sure whether you are looking at a marigold or zinnia based on the flower, take a look at the leaves. Marigold leaves have lacy, frilled edges, like fern leaves. The leaves of marigolds also have a strong scent. Zinnia leaves taper to a point with smooth sides, like a pointed oval.