Zinnias are flowering annual plants native to warm areas of North America. Gardeners value the plants for their large, showy blossoms that are often used in cut flower arrangements. Easy to grow and care for, zinnia plants are frequently grown directly from seeds. They produce abundant flowers throughout the summer and early fall when provided with the proper culture. Zinnia flowers are great for use in flower beds, borders and edging.

How to Start Zinnia Seeds

Start zinnia seeds indoors four to six weeks before the last frost-free date in your area or direct seed in the garden after the soil has warmed to a workable temperature and all danger of frost is over. If direct seeding, cover lightly with soil, water and wait for germination, which takes about one week. If starting zinnias indoors, cover seeds lightly with high-quality soil starting mixture, keep moist and provide with indirect light until ready to set out.

How to Grow Zinnia Seeds

Once the plants have been set out and/or the seeds have germinated, water about once per week until established. After this, water only during dry periods or when temperatures are extremely high. Feed once or twice per month with a liquid fertilizer made for flowering plants and pinch the tops of the plants after they've grown at least 4 inches to promote bushy growth.

Zinnia Cultivars

When purchasing zinnia seeds, you have a wide variety from which to choose. There are more than a dozen actual species of zinnia, but only a few are regularly planted in gardens. Following are some of the most popular types.

• Zinnia elegans - This is the most common cultivar with solid- and multi-colored flowers that bloom in all different shades. Numerous hybrid varieties exist.
• Zinnia augustifolia - This cultivar features smaller, golden-orange flowers with yellow stripes and reaches heights of up to 12 inches with a 2 foot spread.
• Zinnia pauciflora - This is a rarer cultivar that produces single flowers in shades of red or yellow. It is often used for cutting when available.