Zinnia (group)
Common Name: zinnia 
Type: Annual
Family: Asteraceae
Zone: 2 to 11
Height: 0.50 to 4.00 feet
Spread: 0.50 to 1.50 feet
Bloom Time: June to frost
Bloom Description: All but blue and brown
Sun: Full sun
Water: Medium
Maintenance: Low
Suggested Use: Annual
Attracts: Birds, Hummingbirds, Butterflies
Tolerate: Black Walnut

Culture

Annual. Easily grown in humusy, evenly moist, well-drained soils in full sun. Sow seed directly in the ground after last frost date and, if desired, at 2-3 week intervals thereafter until the end of June to insure a good season-long bloom. For earlier spring bloom, start seed indoors 4-6 weeks before last frost date. Some varieties are widely available in cell/six packs from nurseries (small plants that have not yet flowered are best). Disease-resistant varieties are good selections for hot and humid summer climates such as the St. Louis area. Set out seedlings and purchased plants after last frost date. Pinch young plants to promote compact, bushy form. Good air circulation helps prevent onset of fungal leaf diseases. Deadhead spent flowers to promote additional bloom and maintain plant appearance.

Noteworthy Characteristics

The genus Zinnia contains about 17 species of annual, perennial and low shrubs native to the southwestern U.S., Mexico, Central America and South America. Cultivars of several species are commonly grown for their colorful daisy-like flowers over a long summer to fall bloom period.

Genus name honors Johann Gottfried Zinn (1727-1759), professor of botany, Gottingen.

Problems

Susceptible to powdery mildew, leaf spots, root rots and blights. Watch for whiteflies, aphids, thrips, Japanese beetles and caterpillars.

Garden Uses

Mixed borders, beds, cottage gardens, cutting gardens and containers. Many are excellent fresh cut flowers.