George WeigelThe ‘Zahara’ series of zinnias are more trouble-free than most zinnias.
Q: My zinnias are really being wiped out this year. I’m suspecting a bug. Sevin dust has helped somewhat. Some of the leaves have holes in them, and a few plants are turning brown and dying. I have had zinnias before in a different area of the yard, and did not experience this.
A: Zinnias can be prone to several bugs as well as the most common problem — powdery mildew, which is a disease that turns the leaves whitish, then brown.
The holes could be due to Japanese beetles or to a couple of other smaller beetles that sometimes eat zinnia leaves. But none of those would typically cause whole plants to brown and die.
Leafhoppers are another zinnia-attacking bug that make spots on the leaves but also spread a disease that can kill the plants. So that’s a leading possibility here.
Aphids and mites are smaller bugs that don’t chew holes but cause more of curling and/or mottling damage to the leaves.
It’s possible you have more than one problem, too — say beetles or leafhoppers that are making the holes and a disease that’s browning the foliage.
I’d first look closely at the plants to see if you see any bugs or evidence of bugs, i.e. sticky “honeydew” (waste) on the stems (aphids) or tiny bugs that jump up off the plants as you disturb the leaves (leafhoppers).
Sevin kills most bugs. Insecticidal soap (an “organic” option) also is fairly effective against a variety of bugs, although you may have to spray it several times and hit the bugs with it to clear up an infestation.
If there’s no sign of bugs and the leaves are just discoloring from white to brown, a fungicide spray would be the answer to mildew. Most fungicides you’ll encounter in garden centers are labeled for mildew control.
In my garden, I hardly ever get into spraying. I try to keep my plants as un-stressed as possible and then rely on natural predators to clear up problems. De-stressing includes picking good varieties in the first place, growing them in good soil and the right light exposure, and keeping them watered in hot, dry weather — and especially when young.
Plants that don’t make it under those conditions get edited out of my yard in the future. Or I’ll try a different variety at the very least.
Zinnias, for example, do best in full sun and compost-enriched soil. But most of the older varieties are so prone to mildew (and occasionally bugs) that I stick mainly with the compact new zinnia series ‘Profusion’ and ‘Zahara.’ Both of these come in a variety of colors, and I’ve found them to be largely trouble-free.
Zinnias: The Hardest-Working Flower in the Summer Garden
In summer, gardening requires plants with three key qualities: low maintenance (it’s hot out there), heat and drought tolerance (ditto), and brilliant color—the brighter the better.
Zinnias fit the bill on all three counts. And more. In fact, they’re one of the best flowers that smart gardeners can put to work in their gardens.
Zinnias work fast.
If there’s an easier flower to grow, we’d like to know about it. Zinnias are annuals, meaning that they go from seed to flower to seed quickly. Zinnias’ pointy seeds, shaped like little arrowheads, require only basic garden prep to sprout: sow them in well-drained soil, where there’s full sun and lots of summer heat, and you’ll have tiny seedlings in days, with flowers powering up in just a few weeks. No perennial can claim that speed!
One gardening friend doesn’t even bother to prepare her soil—she simply sprinkles seeds wherever she’d like a few zinnias, waters those spots for a couple of days, and lets zinnias’ easy-to-grow nature take its course.
Zinnias work wherever you need color.
Aside from fresh color, many new zinnia series offer height and width options, too.
- While the tall versions of Zinnia elegans remain the classic choice for the back of the border, shorter series now challenge the low ground once ceded to marigolds and petunias. The Magellan Series stay close to knee high at 14 inches, while the Thumbelina Series of dwarf zinnias peak at 6 to 8 inches.
- Creeping or spreading Zinnia angustifolia, such as the Crystal Series, are a revelation for the front of the border, raised beds, containers, and even ground covers. This Mexican native is the go-to species for hot spots like sidewalk beds or that no-man’s-land beside the garage, since it’s even more drought tolerant than common zinnias.
- Zahara™ zinnias top out at just 8 to 12 inches—and are prized for their resistance to powdery mildew and leaf spot (see below). Zahara Yellow is short but sweet—we paired it with petite sunflowers in the entry beds at the Regenstein Fruit & Vegetable Garden.
Zinnias work as cut flowers.
Zinnias have style, in addition to long, strong stems, so they are naturally destined for the vase.
Wonderful language gets used when describing zinnia flowers: stars and daisies, dahlias and spiders, buttons and domes, and quill-leaf cactus. Flowers can be “singles,” with petals lined up in a row around an open center, or semi-doubles, or doubles. All work marvelously in floral arrangements.
Of course, the tall varieties are the zinnias of choice for cutting: ‘Benary’s Giant’ is famous for its three-foot-tall, sturdy stems and large flowers. Cut zinnia stems at an angle just above a bud joint. Zinnias are typically long-lasting in a vase—strip the stems of all but the most visible leaves before setting them in water.
Zinnias cut your workload.
Zinnias are low maintenance. Since they’re fast-growing, they shade out weeds. They don’t require much in the way of fertilizing (just an occasional well-balanced mix), and they don’t need mulching.
Deadheading helps to produce more flowers. No time to deadhead? The Zaharas mentioned in the sidebard are self-cleaning—a real time saver when it comes to a large bed.
Like Zaharas, the Profusion Series (hybrids between Z. elegans and Z. angustifolia) are resistant to the scourge of zinnias: powdery mildew.
Because zinnias are native to the grasslands of the southwestern states, Mexico, and South America, they know how to handle dry conditions. But wet summers (we’ve had one so far) can take their toll. And that can lead to powdery mildew and leaf spot. Three suggestions for dealing with wet conditions:
- Water only when needed, and then only at the base of the plants. Wet leaves can promote mildew development, and splashing water can transfer fungus from the ground onto zinnia leaves in an instant.
- Camouflage tall, more mildew-prone varieties with other plants in the foreground.
- Do both #1 and #2 and live with the fact that zinnia leaves (but not flowers) are affected by wet weather—as one horticulturist put it, “Even when zinnias are covered in powdery mildew, they’re covered in flowers.”
Zinnias work year after year.
It’s easy to save zinnia seeds. Simply let the flowers dry fully on the stem, then collect the seedheads and lightly crush them in your hand to release next year’s seed crop. Store in a cool, dry place as you do other seeds. (And set some aside in a labeled envelope for our Seed Swap next February!)
One last reason to plant zinnias year after year: they’re butterfly magnets. The bigger-flowered varieties act like landing pads for nectar-seeking butterflies. (Same goes for hummingbirds.) Try tall zinnias with red or hot pink flowers to get the biggest draw.
Zinnias are annual plants in the Asteraceae family that offer a wide variety of heights, colors, and types of flowers. Zinnias are very easy to grow and require little maintenance but offer bright, showy flowers. They attract butterflies and make excellent cut flowers.
Plant heights range from 6 inches to several feet tall. Zinnias can be grown in zones 1 through 10. They prefer well-drained, fertile soil and should be grown in full sun.
How to Grow
Sow zinnia seeds directly into the soil, after the last frost. Cover with ¼ soil and keep soil moist until the seeds germinate, in about 4 to 7 days. Plant in soil that is well-drained but fertile and is located in full sun. Consider adding compost to loosen and fertilize soil and to help retain moisture.
Especially in humid areas, zinnias need air to circulate around the base of the plant, so thin seedlings to about 6 to 8 inches apart for shorter varieties and 12-18 inches apart for taller varieties. This can be done when the seedlings are about 3 inches tall. Keep seedlings fairly well watered until they are more mature.
Pinch or cut of dead flowers (generally at the base of the next closest leaf branch, being careful not to damage any leaves or buds) to encourage bushier growth and more flowers.
Zinnias will reseed themselves, but if you’d like to save the seeds to use next year, simply leave some flowers on the stalk until they appear dry and brown. Cut off the flowers and flake out the seeds into a bag. Generally, the seeds are attached to the base of the petals in zinnias.
In the humid southeast, zinnias are susceptible to powdery mildew, which begins to show up in late summer. If this is a problem where you live, there are some mildew-resistant varieties to try instead of the traditional seeds. Additionally, water plants at the ground instead of spraying from above to reduce mildew problems.
Powdery mildew-resistant varieties include
- Zinnia angustifolia
- Zinnia haageana
- Blue Point series
- Pinwheel zinnias
- Profusion zinnias
- Zahara zinnias
Try searching for “mildew resistant zinnias” to find other mildew-resistant varieties.
Flowers That Plant Themselves
Jean Allsopp, Van Chaplin, Allen Rokach
For continuous color, you can’t beat annuals. But some people can’t bear to spend money on plants that die with the first autumn freeze. “People tend to downplay annuals because they think they have to replant them every year,” says Linda Hostetler of The Plains, Virginia. “That’s not necessarily true. If you choose reseeding annuals, they’ll come back everywhere.”
You need only look at the gardens presented in this special section to understand just how right Linda is. Each one derives much of its seasonal color from flower seeds you buy and sow only once–plants such as poppies, larkspurs, coreopsis, and cosmos. After they finish flowering, their seeds drop to the ground, and then new plants magically appear the following year.
Self-sown seedlings, often called “volunteers,” sometimes show up in unexpected places–gravel paths, cracks between rocks, or right in the middle of a clump of something else. This randomness gives a cottage garden its charm and surprise. And if you don’t like where something sprouts, it’s okay to yank it up.
Tricks for Planting
Seeding flowers in the garden does require a little bit of know-how. For example, if you want the seeds to sprout, you had better not mulch or apply a pre-emergence herbicide.
The procedure for seeding by hand goes like this.
- Select an empty spot.
- Prepare the soil by adding any necessary amendments, such as compost, peat, or ground bark.
- Rake the soil surface smooth, removing rocks and sticks.
- Sow seeds evenly over the soil, using a rake to barely cover them; then water gently.
When should you sow them? Spring or fall is fine for most flowers. However, for those that bloom during the cool weather of spring, such as poppies, larkspurs, sweet Williams, and love-in-a-mists, fall is the only option. Most of the flowers listed in the box prefer full sun; the ones that do well in shade are noted by asterisks.
Blooms That Come Back
- bachelor’s button (Centaurea cyanus)
- clasping coneflower (Dracopis amplexicaulis)
- coleus *
- crested cockscomb (Celosia argentea)
- forget-me-not *
- impatiens *
- Indian blanket (Gaillardia pulchella)
- Indian paintbrush (Castilleja indivisa)
- love-in-a-mist (Nigella damascena)
- money plant (Lunaria annua) *
- opium and Shirley poppies
- Queen Anne’s lace (Daucus carota carota)
- spider flower (Cleome hasslerana)
- sweet William
* Will grow in shade
After the Blooming
Once flowers set seed, you can let the plants drop them on the soil and wait to see what comes up where. Or you can collect the seeds and sow them at the proper time according to the above procedure. Either way, a small investment of money and time will bring you many happy returns.
Zinnia is a genus of the annual and perennial plants of the family Asteraceae. Zinnias come in 20 species of composite flowers. The flowers are ideal for indoor arrangements. Zinnias bloom in a wide variety of colors with large, mixed blooms.
Kingdom Plantae Division Magnoliophyta Class Magnoliopsida Order Asterales Family Asteraceae Genus Zinnia
One of the easy to grow annual flower, Zinnias bloom from mid-summer all the way until frost. About 10 species of Zinnia are garden flowers but only the Zinnia elegans is most popular. Zinnia elegans originated in Mexico and therefore, likes a arm-hot climate. The Zinnia plant’s leaves are lance-shaped and sandpaper like in texture. The Zinnia plant’s height ranges from 15 cm to 1 meter.
Zinnias come in an array of colors, multi-colors and hues. Zinnias come as yellow, orange, white, red, rose, pink, purple, lilac and multi-colored blooms. Zinnia varieties include both miniatures and giants that range from about a foot to over three feet tall.
Zinnia flowers come in a reage of appearances, from a single row of petals, to the dome shaped variety. Hardy plants,Zinnias have erect stems that bear opposite leaves and terminal flower heads. The Zinnia species with small, orange flowers is Zinnia augustifolia, while the species with red, purple, or yellow petals is Zinnia peruviana.
Did you know? Butterflies are particularly attracted to Zinnias. So, plant lots of Zinnias if you want many butterflies visting your garden!!
Facts About Zinnias
- The name of the genus derives from the German botanist Johann Gottfried Zinn’s name
- There are two species of zinnia that occasionally obtain attention as ornamental plants, the Zinnia grandiflora and Zinnia tenuifolia.
- The common Zinnia of gardens, Zinnia elegans, is also called youth-and-old-age.
- The most popular bedding plants, Zinnias originally grew as wildflowers native to the southwest United States, Mexico and Central America.
Did you know? Zinnia was the state flower of Indiana during 1931 – 1957.
from our stores – Pickupflowers – the flower expert
- Generally, Zinnias are grown from seed.
- Zinnias need fertile, humus-rich, and well-drained soil. They reseed themselves each year.
- Zinnias need full Sun.
- Zinnias like rich, well drained soil. Good soil quality will produce much healthier plants and flowers.
- Sow the zinnia seeds by putting one seed in approximately every square foot.
- Lightly rake the seed bed, and plant the seeds about 1/4 inch deep.
- Apply fertilizer as needed.
- Water the seed bed.
- Add a general purpose fertilizer once a month.
- Water Zinnias during dry periods, once or twice per week. Soil should be moist, but not wet.
- Add mulch around the plants for appearance and to keep weeds down.
Zinnia Plant Care
- Remove dead flower blooms to encourage new growth and new blooms.
- Improve appearance of Giant Zinnias by trimming back stems that have grown long, but do not over trim them.
- Zinnias are annuals and are susceptible to frost. They may survive the first light frost with only a little damage.
- Zinnias will not survive a hard frost or freeze.
- Zinnias are a little resistant to insects and disease.
- If insect or disease problems occur, treat Zinnias early with organic or chemical insect repellents and fungicide.