Zinnias add easy color to your garden GO ANNUAL
By Michael McBride
OSU Extension master gardener volunteer
As you begin to clean up your flower beds and prepare for the growing season, think about adding some easy color to your garden.
Annuals (grow one season) can add easy color. There are unlimited numbers of annuals you can plant, but I want to make you aware of an easy, often overlooked variety.
Zinnias are easy annuals to grow. They are native to the Southwestern United State to South America with the most abundant diversity in Mexico.
Zinnias are part of the asteraceae (asteracia) plant family which includes asters, daisies, sunflowers and marigolds.
Zinnias are diverse in color, size and flower type. They can be red, yellow, orange, purple, pink, white or even green. They also can be multicolored.
Zinnia can be as small as a few inches all the way up to 40 inches, depending on the variety. Flowers can be as small as an inch or up to 5 inches across. Flowers can be single flower row, double row or even dome shaped.
Zinnias can be purchased in garden centers, nurseries or big-box stores in limited selection.
Seeds are your best bet for unique types. They can be started from seed indoors four to six weeks before the last expected frost, or they can be sown directly into the garden when soil warms sufficiently. It usually takes five to seven days for zinnias to germinate.
When planting, zinnias do best in full sun and in fertile, well-drained soil. Plants can be spaced up to 24 inches apart depending on the variety. When growing for cut flowers, crowd plants to encourage longer stems. Pinch the tops when they are 4 to 6 inches tall for bushier plants.
Zinnias don’t require excessive water, but they shouldn’t be allowed to dry out. They grow well when the weather is humid and they are heat tolerant. When watering, water from the bottom to avoid getting wet leaves. Powdery mildew can become a problem if the leaves get too wet and remain wet. You will probably notice white mildew on the leaves in late summer or fall when the dew gets heavy, the days get cooler and daylight begins to shorten.
Zinnias will bloom from early summer to the first frost. Deadheading, removing faded flowers, encourages more blooms.
Infrequently, they may attract aphids. Japanese beetles can be a pest that bothers zinnias, but they can usually just be removed.
The central flower of the zinnia is visible and produces nectar for bees and butterflies. Humming birds also visit. Their ability to attract hummingbirds is also seen as a defense against whiteflies; therefore, zinnias are a desirable companion plant, benefitting plants that are intercropped with it.
Since zinnias will not survive a hard frost, you may want to select a few dried seed heads (the center of the flower) that are mature and place them in a paper bag. Label the bag and store it either in a cool spot or your refrigerator. Next spring you should have useful seeds to plant.
Check out all the zinnia varieties available in many seed catalogs. Choose the ones you like and begin the process of adding color to your garden.
To learn more about options available, go to http://go.osu.edu/zinnias.