Zinnia

Zinnia is a warm-season flowering upright growing annual in the Asteraceae (daisy) family. They are native to southern North America and South America, and there are many cultivars, colors, and a range of sizes available—from 8 inches to 4 feet tall. Zinnia is named in honor of Johann Gottfried Zinn, a German botanist.

Zinnia is showy, low maintenance, and easy to grow. Plant them in average, well-drained garden soil in full sun and allow good air circulation. Keep them moist until established. Deadhead to encourage more blooms but leave some seed heads for the birds.

Zinnia comes in various shapes, including beehive, button, and cactus. Before the flowers open, the bracts appear as overlapping fish scales. As the flower opens the bracts are visible on the undersides of the flower. The inflorescence is a composite head. The petals appear as ray flowers, and they may have star-shaped disc flowers. The ratio of ray flowers to disc flowers is variable. Their blooms may be described as single (single row of petals and a visible center), double (numerous rows of petals, centers not visible), or semi-double (numerous rows of petals with visible centers). The leaves are ovate to lanceolate with some plants having more linear leaves. The leaves have no petioles and are sessile, clasping, and opposite in arrangement.

There are multiple varieties or cultivars of zinnia, including the hybrid 'Profusion' Series. A cross between Zinnia angustifolia (disease resistance) and Zinnia elegans (larger flowers), ‘Profusion’ combines the best traits of both, including tolerance to drought, heat, and humidity. The strong, durable foliage resists insects.

Depending on the size, zinnias can be used in the front or the back border, in a meadow, in containers, and a cutting or pollinator garden. Massed or in small groups, they add season-long color to the landscape. Zinnia is deer and rabbit resistant and attracts butterflies, hummingbirds, and songbirds. 

Seasons of Interest:

Bloom:  Spring, Summer, and Fall    Foliage: Spring, Summer, and Fall

Quick ID:

• upright growing from 8 inches to 4 feet tall
• ovate to lanceolate leaves with some cultivars having linear leaves
• sessile, clasping and opposite leaves
• bracts appear in an overlapping fish scale pattern before the flower blooms
• flowers have a composite head, ray flowers, and star-shaped disc flowers
• ratio of ray and disc flowers is variable

Insects, Diseases, and Other Plant Problems: Susceptible to powdery mildew. 

The Clemson Cooperative Extension Home and Garden Information Center has a factsheet on common zinnia insect pests and diseases.

 VIDEO Created by Elisabeth Meyer for "Annuals, Perennials, Vines, and Groundcovers" a plant identification course offered in partnership with Longwood Gardens.