Cooperative Extension Service 
Institute of Food and Agricultural Sciences
Hendry County Extension, P.O. Box 68, LaBelle, Florida 33975-0068  Phone (863) 674-4092

Hendry County Horticulture News

Zinnias - Tried and True Color

One of the best investments, I have ever made was a ninety five cents pack of zinnia seeds that I chanced to purchase several years ago.  The progeny and the descendants of the zinnias that grew from these seeds have faithfully provided a pleasing riot of joyful color to my garden on a yearly basis ever since that initial investment.  More often then not, these lovely annual flowers have self seeded so that they have had a prominent place in the flower bed near the entrance of my humble abode, with little or no help from me, ever since they were first planted many years ago.  While the monetary savings may be negligible, the pay back in visual beauty, bright colors, and the joyous spiritual uplift that they have provided has been priceless.

Zinnias are prized for beds, borders, containers, and cutting gardens.  They are perhaps at their best in mass plantings.  In terms of tried and true flower varieties, zinnias are rivaled only by marigolds in creating cheerful masses of color in the garden and providing cut flowers for the house.  Zinnias are easy to care for plants that tolerate a wide range of soil conditions.  They perform best in fertile well drained soil in full sun. Zinnias prefer warm weather and in our area are best planted in February through March for spring and summer flowers and in September to October for fall color.  While many warm season flowers will fade when the rainy season begins, zinnias can be replanted during the summer season.  In fact, zinnias are one of the few stalwarts that can withstand the full rigors of the south Florida summer.

Zinnias are available in a variety of colors and a range of shapes from ruffled and semi-ruffled "dahlia-types" and quilled "cactus-flower" types to tiny pompons.  Zinnia elegans is the zinnia most often grown in gardens.  The flowers may come in single or doubles types and are colored in bold shades of pink, magenta, cherry, orange, yellow,  white and even green.  Both solid and bicolor forms are available.  The well branched plants are generally stiff and upright and usually stand up well in the garden.  The taller cultivars can topple in stormy weather may require staking to stay upright.  If you neglect to stake your plants and they go sprawling over, don't worry.  Zinnia plants are able to send out new roots along stems that come in contact with the soil, enabling them to fill up empty spots in beds without assistance.  You might even want to encourage this process by laying down and pinning extra long stems to the ground to help fill vacant places.

Two other species of zinnia are sometimes encountered in seed catalog and garden shops.  Zinnia augustifolia is a narrow leafed zinnia with small daisy like yellow, orange, and white flowers with orange centers. This variety tends to sprawl on the ground and can be used as an annual ground cover or in planters or patio containers.  "Pinwheel" types are a cross between Z. elegans and Z. augstifolia.  They combine the larger flower size of Z. elegans with the mildew resistance and single flower form of  Z. augstifolia. These cultivars are available in cherry, orange, rose, salmon, and white.

Zinnias are easy to grow.  Prepare flower beds by improving the soil with a liberal addition of compost, manure or other suitable organic material.  Fertilize the soil with one  pound of complete fertilizer such as 6-6-6 per one hundred square feet.  Till the soil completely and you are ready to plant.  Zinnias may be direct seeded into garden.  Transplants, however, will produce flowers in a much shorter time.  Irrigate as needed  to maintain rapid growth and flower production.  To ensure continued production of flowers, removal of spent blossoms is a must.  Cutting blooms for fresh flower arrangements will produce the same result.

In our area, zinnias will self-seed if the flowers are left to mature.  Under favorable conditions, they will produce several crops per year in the same location with just a little assistance from you in the form of additional compost and fertilizer on a regular basis.  Zinnia elegans seed may also be saved for future plantings.  Be sure to select well dried seed heads from healthy plants and store them in a dry location.  Be sure to select seed heads from flowers of different hues to obtain a good mix of colors for subsequent plantings.

Zinnias are relatively pest free.  They are susceptible to two fungal diseases: powdery mildew, which produces powdery white patches on the foliage and causes plants to decline: and alternaria, which causes leaf spots.  Wide spacing to allow for good air circulation will help reduce the incidence of these diseases.  Infected leaves can be pinched off and destroyed as detected.  Fortunately, these diseases generally do not greatly affect the plants until they are past maturity and in a state of decline.  Zinnia augustifolia and pinwheel cultivars are resistant to powdery mildew.

For bright summer color, why not get back to basics and give zinnias a try.  Good luck and good gardening.

Gene McAvoy is the horticulture agent with the Hendry County Extension Service.  Direct your horticulture questions to PO Box 68, LaBelle, FL 33975,  e-mail - or phone 863-674-4092 or 863-983-1598.  You are also welcome to visit the Hendry County Extension Office at 225 Pratt Blvd., LaBelle.   Office hours are from 8:00 - 5:00.

The Institute of Food and Agricultural Sciences is an Equal Employment Opportunity - Affirmative Action Employer authorized to provide research, educational information and other services only to individuals and institutions that function without regard to race, color, sex, age, handicap or national origin.

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