Zinnia is a genus of plants in the family Asteraceae, native to scrub and dry grassland in an area stretching from the Southwestern United States to South America, with a center of diversity in Mexico. The most distinguishing characteristic of the flowering herb is its bright yellow-orange to red inflorescence of composite flowers. Zinnias are annuals, shrubs, and sub-shrubs that typically range in height from 10 to 100 cm tall (4" to 40"). They are popular garden flowers because they come in a wide range of flower colors and shapes, and they can withstand hot summer temperatures and are easy to grow from seeds. Zinnias prefer full sunlight and well-draining soil. They are easy to grow with potential heavy blooms that gush in color. Their petals can take different forms as single row with a visible center (Single-flowered zinnia), numerous rows with a center that is not visible (Double-flowered) and petals that are somewhere in-between with numerous rows but visible centers (Semi double-flowered zinnia).
Here are some step-by-step instructions for taking care of zinnias: Planting: Zinnias can be grown from seeds or purchased as seedlings. They prefer full sun and well-draining soil. Water them regularly, keeping the soil evenly moist but not waterlogged. Watering: Zinnias require regular watering throughout the growing season (spring to fall). They need at least an inch or two of water every seven to ten days. If the rain doesn’t provide it, you should. Fertilizing: To stay healthy during the months-long blooming marathon, zinnias need a dose of diluted liquid fertilizer, provided once every month or so while they’re flowering. Select a balanced product (10-10-10 NPK). Pruning: Prune zinnias regularly to encourage bushy growth and more flowers. Deadheading spent blooms is also important to keep the plant looking tidy and to encourage more blooms. Propagation: Zinnias can be propagated by stem cuttings taken in late summer or early fall. Trim off a healthy portion of stem that’s around 6 inches long. Opt for a green, supple stem over one that’s older and… Remove foliage from the bottom half of the stem. Dip the cut end in rooting hormone. Plant the stem in a small container filled with moistened soilless potting mix.