Zinnias: An Herb That
Became a Favorite Flower
by James Kambos 
By the first week of July, my herb and flower garden is splashed with color. The monarda raises its shaggy red flowers atop fragrant stems here and there. The shasta daisies with their white and yellow flowers always look crisp and fresh. Towering above the coreopsis, the sweetly scented flowers of tall purple phlox look relaxed no matter how hot it is. But, beyond the daylilies in the lower end of my garden, standing bold and tall, are my favorites—the zinnias. Beneath the July sun, the rich colors of their petals still seem to hold the warmth of Mexico and the American Southwest, the regions where they originated.
Yes, it’s true they make no apology about being bright and showy. Some people have even said “brassy.” But for me it’s not summer without zinnias!
Zinnias belong to the Asteraceae family, along with asters and daisies. Their genus is Zinnia, which contains about twenty species. Only three species are garden worthy: Zinnia elegans, Zinnia angustifolia, and Zinnia haageana. There are at least a hundred varieties available, and the list continues to grow.
A Forgotten Herb
Most of us know the zinnia as a cheery, bright annual flower that has been around since Great-Grandma’s day. However, the zinnia is also considered an herb because it was once used as a dye plant. No matter what color petals are used to create the dye, all zinnias yield a dye that is yellow to warm gold in color. The only color zinnias don’t come in is blue. Some varieties even come in green, or actually, a pale chartreuse.
I frequently refer to zinnias as a “forgotten herb” because few people know about its history as a source for dye. Most of the herbalists that once used zinnias to make dye are long gone. So, the zinnia is an herb as well as a pretty annual flower.
Zinnia History
Zinnias date back to the 1500s when the Spanish discovered them growing as a wildflower in Mexico. At the time, they were considered a weed. Then around 1750 the German ambassador to Mexico sent some seeds belonging to this wildflower to a German doctor, Johann Gottfried Zinn. Dr. Zinn was a brain and eye specialist, but he had a passion for botany. He studied these seeds and wrote the first scientific study about these nondescript Mexican flowers. Eventually, these plants were named zinnias in Dr. Zinn’s honor.
Later, in the 1850s, the French developed a double zinnia form. Soon the plant world took notice. In the early 1920s the first dahlia-type zinnia was developed in America by Luther Burbank.
It didn’t take long after that for American seed companies and their researchers to create many beautiful new forms of zinnias. What began as a weedy Mexican wildflower became one of America’s top-selling annual bedding plants by the late twentieth century. Sales of zinnias are rapidly increasing. In fact, a major garden center in my area actually ran out of zinnias during the 2017 planting season. Many zinnia suppliers have begun reporting that zinnia plants are now a leading moneymaker for them.
Planting and Growing Zinnias
Few herbs or flowers give back so much beauty with so little effort as zinnias do. Give them average to fertile soil, sun, and occasional deadheading, and zinnias will make their way with little help from you.
Zinnias may be planted in two ways. You may sow the seeds directly into the garden, or you can buy established plants in plastic pots available at garden centers. I use both ways depending on my needs. For planting in the cutting garden or for large areas, I prefer seeds. Zinnia seeds sprout quickly and are economical. If I need some quick color or if I have some bare spots after the growing season begins, then I’ll use potted zinnias. Either way, zinnias should be planted after all danger of frost has past. In my Ohio garden this is usually early May.
To direct sow the seeds into the garden, weed and loosen the soil. Add topsoil or compost if needed. Level the soil with a hoe. Scatter the seeds evenly, cover lightly with soil, and keep the seed bed moist until the seeds sprout. I’ve even scattered the seeds on top of the prepared soil without covering completely, and they did fine.
To plant potted zinnia plants, simply dig a hole large enough for the plant. Then remove it from the pot and place in the planting hole. Firm the soil around the base of the plant and water.
Zinnias also make a great companion plant in the vegetable garden. A few zinnias, or a row of them, planted among your vegetables help deter many destructive insects and worms.
No matter where you plant them, zinnias attract bees and butterflies, which are beneficial to the garden. Deadheading is recommended to encourage flower production, but I let a few of my zinnias go to seed to attract goldfinches—they love the seeds.
Zinnias are not attractive to deer. They can safely be planted in areas that have a large deer population.
About the only problem zinnias are sometimes afflicted with is powdery mildew. This is a fungal disease that causes a white powder-like growth to form on foliage, stems, and sometimes flowers. To prevent this, be sure your zinnias are well spaced and get good air circulation. Another preventive measure is to water zinnias early in the day. This will allow the plants to dry thoroughly.
A Few Zinnias to Get You Started
There are about a hundred varieties of zinnias available. They come in a rainbow of colors and a variety of shapes. Some are dahlia shaped, some are double, and some even have spidery cactus-shaped petals.
It’s easy to find a zinnia you’ll love. Since I can’t write about all of them, I’ve come up with a list of my favorites. These are zinnias I’ve grown. I’ve seen how they perform in heat, drought, and humidity. They’re winners!
The zinnias I’ve selected will keep your garden colorful from early summer to hard frost. You’ll also have enough for cutting.
‘California Giant’: This is probably the zinnia Grandma grew along a fence. Stems grow three to four feet, and the flowers can grow up to five inches across. It usually comes in a seed mix of red, yellow, orange, white, pink, and purple. The flower form is slightly flat and open. This heirloom variety has been adding charm to gardens since 1926.
‘Enchantress’: The flowers of this stunning pink zinnia are held above sturdy three-foot stems. This is the zinnia that will have people saying, “I can’t believe that’s just a zinnia!”
‘Oklahoma Mix’: This zinnia was bred for its superior cut-flower qualities. It produces loads of flowers on thirty-inch stems. Flowers are semi to fully double and one and a half to two and a half inches wide. Colors include white, salmon, yellow, and pink. It’s extremely resistant to powdery mildew.
‘Persian Carpet’: Also known as Mexican zinnia (Zinnia haageana), this extremely drought-resistant zinnia grows on stems only sixteen inches tall. Its two-inch flowers are usually bicolored in shades of red, burgundy, yellow, and gold. The foliage is narrow. It looks great at the edge of a flower bed or in a wildflower garden. I plant mine near a clump of thyme, and they look great together.
‘Profusion’: This zinnia hybrid is a powerhouse of vigor, disease and heat resistance, and bloom. Colors include cherry, white, yellow, orange, pink, and apricot. The two-inch flowers almost cover its attractive narrow leaves. They’re fantastic massed in the landscape or singly in front of the border. It also does well in pots. It grows to eighteen inches with a twenty-inch spread. ‘Profusion’ does very well in very hot areas, such as along pavement. No need to deadhead.
‘Star’: This hardy zinnia smothers itself with two-inch flowers from summer to fall. Its flowers come in white, yellow, and orange. It grows to about fourteen inches, with a mounded spreading shape about a foot wide. ‘Star’ is lovely planted at the edge of a raised bed where it can cascade over the side. It’s not bothered by heat or drought, and deadheading is not required.
The herbalists of long ago valued the zinnia for the yellow-gold dye its petals gave. That dye probably brightened the lives of the pioneers as they moved west. Thanks to the magic of plant breeders, the zinnia is still brightening our lives today. Whether in the garden or in a vase, zinnias will always be valued for their beauty and charm.