Colorful, versatile and easy to grow, zinnias are the perfect flower for a beginning gardener. Best of all, they thrive in the summer heat of the Coastal Bend.
Aside from blue, zinnias come in every color under the sun, and some varieties even present multiple hues across the same flower. They create a stunning display, whether densely planted in the garden or arranged as cut flowers in a vase. The sturdy green stems stand tall, adorned with small, needle-like green leaves.
In the Coastal Bend, zinnias are best treated as annuals, as the plants can survive a mild winter but don’t thrive in the cold. They are easy to grow, requiring little effort to start a new crop each spring. However, if protected from frost and freezes during winter, these flowers can become an intensive ground cover.
The secret to a lush and dense growth of zinnias is to cut back the plants when they are young. Once the plants reach eight to 10 inches in height, clip the top four inches from each stem. This causes multiple stems and flowers to develop. As plants mature, take flowers often to promote continuous blooming.
Although zinnias grow well in the heat of August, they require a lot of water for nice blooms. These flowers must be watered deeply several times per week during summer. Try to water the soil at the base of the plants and keep the leaves and flowers dry.
Zinnias also make fantastic potted plants. Plant one zinnia per six square inches of space in each pot and place them outside in full sun or indoors in maximum sunlight. Outdoor potted zinnias should be watered every other day in August.
Zinnias are available in many colors and sizes as transplants at local nurseries, from tall to dwarf varieties.
Gardener’s Notes
Growing Up: Spacing, 8” to 10”. Height, 8” to 16”. Full sun; some afternoon shade. Any well-drained soil. Best planted as a transplant. Add organic compost to the soil and two cups of pastured poultry manure per plant. To plant from seed: prepare bed, hand broadcast seeds, gently rake into soil, thin to final spacing. Zinnias require frequent, intensive watering during summer. Water the base of plants; try to keep the stems and flowers dry to prevent fungal diseases.
Profiling: Take blooms or deadhead often for continuous flowering. For best cut flowers, harvest only mature blooms. Hold the stem six to eight inches below the flower and wiggle it to tell when a zinnia is ready to harvest. If the flower is stiff, it is ready to cut. If it bends or wobbles, it is not yet prepared. Mature flowers look best and last longest in the vase. Do not refrigerate cut zinnias.
Fun Facts: Zinnias are native to Mexico, and Aztecs used the flower in religious festivals. Hernan Cortez sent zinnia seeds to Europe, where German botanist Johann Zinn first described the plant. Linnaeus himself named the flower “Zinnia elegans,” or the elegant flower of Dr. Zinn. The original zinnia was bred into many colors and sizes in France during the 17th and 18th centuries; these improved zinnia varieties were sent to America, where they finally became popular in the 1900s.
