Growing Zinnias
Zinnias come in all shapes and sizes, but they all feature stunning flowers, often in bold, vibrant hues. Full flowers bloom on the ends of tall stems, usually hovering above the foliage. The blooms make wonderful cut flowers, so trim some to include in an arrangement. Green foliage gives the plants a dense and lush look.
These fast-growing plants bloom from spring through fall and thrive in warm summer weather. Zinnias are native to North and South America.
Planting Zinnias
Plant Zinnias in the spring when there is no longer a chance of a cold swing. Leave adequate space between plants so air can circulate. Cramped growing conditions can lead to mold and fungal issues. Choose a site that receives full sun. At least six hours of sunlight is necessary for these plants to grow and bloom at their full potential. Zinnias can handle poor-quality soil but perform best in fertile soil. Drainage is vital because Zinnias do not like wet or soggy conditions, so make sure the site drains well.
Watering Zinnias
Water new plants immediately after planting. Zinnias are drought-tolerant. Rainfall is often enough to support these plants but monitor them during a dry period. Water if the plants start to show signs of water stress. Water the ground around the plant and keep the foliage dry as much as possible when watering.
Fertilizing Zinnias
Zinnia plants can grow well without fertilizer, but routine feedings support a prolific bloom cycle. Apply a balanced, water-soluble fertilizer monthly from spring through fall. Consistent fertilization keeps the plants lush and in bloom.
Pruning Zinnias
Deadhead Zinnia plants to keep them looking tidy and to prolong the bloom cycle. Remove damaged or dead growth at any time. Thin the plants if you see signs of powdery mildew or a fungal infection. Zinnias are not cold hardy; all growth can be removed after the first heavy frost.
Caring For Zinnias in Pots
Zinnias add vibrant color to a mixed container or window box. Use a container with drainage and fill it with a rich, moist, well-drained potting mix. Potted plants dry out quickly and have increased water needs. Water container-grown Zinnias when the top few inches of potting mix are dry.
Winter Care For Zinnias
Remove dead or damaged growth in the late fall or early winter. Zinnias are not cold hardy and are often grown as annuals. These flowering plants are difficult to grow as houseplants, so plants should be discarded at the end of the season and started fresh in the spring. If you have a heated greenhouse, you can overwinter the Zinnia by trimming it back in the fall and transplanting it into a container with drainage. Water when the top few inches of soil are dry.