About Growing Zinnias

Plant Description

• The species zinnia contains both perennials and annuals. In warmer, frost-free regions, zinnia is more prone to perform as a perennial. It belongs within the family Asteraceae, in which daisies and asters also reside. Zinnia elegans is the most widely grown variety, according to Floridata. There are approximately 100 cultivars of the variety. Depending on the variety, plants grow anywhere from 6 inches to 3 feet tall. Zinnias grow upright and produce thin, lance-like foliage. Flowers range from 2 inches in diameter to as large as 6 inches. Blossom shapes are diverse and include doubles, singles, and cactuslike, dahlia-shaped and small pompons. Flower colors cover the rainbow and include solids, speckles and stripes.

Preferred Conditions

• All varieties of zinnias are frost-sensitive. For optimal growth and blooms, plant zinnia seeds and transplants when outdoor temperature range between 70 and 80 degrees F., as suggested by University of Florida IFAS Extension. Seed germination occurs in seven to 14 days. The plant prefers a sunny environment. It tolerates multiple types of soils that have good drainage. Plant seeds 1/4 to 1/8 inch deep. Plant transplants at the same depth it was growing in the pot. Use containers that drain to prevent fungal diseases and root rot. Grow the plants or transplants in well-drained potting mixes. To prevent disease problems, allow air circulation around plants. Space multiple zinnia plants 12 to 14 inches apart.

Care

• Though zinnia plants are tolerant to dry conditions, watering regularly promotes the best growth. Varieties grown inside containers and growing in hot climates require frequent water applications. If the foliage begins to wilt, saturate the soil with water. Apply water to the ground and not over the zinnia’s foliage, as it promote disease. Fertilize plants monthly using a water-soluble blend. Follow the label’s instructions when applying. Use a zinnia-safe product if insects such as aphids or mites become problematic. If plants develop white, powdery mildew patches on the foliage, use an approved fungicide.

Landscape Uses

• Zinnias have multiple uses within the landscape due to the great variety in plants and growth habits. It makes a colorful and constant blooming addition to mixed, annual and butterfly gardens. Use it in sunny borders or entranceways. Zinnia also grows well inside containers. The blooms will liven up balconies, pool decks or porches. Plant several colored varieties together for a colorful Easter basket effect. Most zinnia varieties produce blooms suitable for cutting.