How to Grow Eye-Popping Zinnia Flowers

Zinnia spp.

With magnificently colorful blooms that put on a dazzling display all summer long, it is no wonder zinnias are such popular flowers.

What’s more, these show-stopping annuals are incredibly easy to grow.

A vertical image of colorful zinnia flowers growing in the summer garden. To the top and bottom of the frame is green and white printed text.

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Continue on to learn how to grow and care for zinnias, and wow all of your neighbors – with barely any effort!

What Are Zinnias?

Zinnia is a genus of flowering annuals in the aster family, Asteraceae, that can be grown in USDA Hardiness Zones 3 through 10.

They feature erect stems with bright solitary flower heads that produce large impressive blooms throughout the summer, attracting hummingbirds, butterflies, and other beneficial insects.

A close up horizontal image of a hummingbird feeding from colorful flowering annuals pictured in light sunshine.

While more than 20 known species exist in the wild, there are only a few species commonly available commercially, and these have been bred into hundreds of cultivars with flowers of many different forms.

Plants can range in size from six inches to four feet tall, with single, double, or semi-double petaled flowers of many different shapes and colors.

A close up horizontal image of colorful annual flowers growing en masse in the summer garden.

Z. elegans is the primary cultivated species. The wild plant has solitary flower heads of about two inches with black and yellow centers and purple petals.

It is native to Mexico, but its original form is no longer easy to find due to cultivars that have escaped into the wild, which have interbred and naturalized in many places around the world.

A close up horizontal image of an orange Z. elegans flower growing in the garden pictured on a soft focus background.
Z. elegans

Z. angustifolia, also known as the narrow leafed zinnia, features smaller single flowers of white, yellow, and orange.

A close up horizontal image of white Z. angustifolia flowers growing in the garden.
Z. angustifolia

Z. haageana, sometimes referred to as Mexican zinnia, has smaller single or double petaled flowers in yellows, orange, and red.

A close up horizontal image of a dazzling red and yellow Mexican zinnia flower growing in a sunny spot in the summer garden pictured on a soft focus background.
Z. haageana.

Both of these species have been crossed with Z. elegans to produce many other varieties.

Cultivation and History

There are many myths floating around about the history of these flowers. It is likely that wild species were cultivated beginning in the 1500s by the Aztecs.

A horizontal image of a garden border filled with colorful annual flowers pictured in bright sunshine.

One story goes that Gottfried Zinn, the German botanist that gave these plants their name in the 1700s, was accosted by bandits while collecting seeds in Mexico.

However, according to Eric Grissell, author of “A History of Zinnias: Flower for the Ages,” this is unlikely to be true, as the supposed occurrence happened 150 years after his death.

At any rate, these enticing flowers found their way from Mexico to Europe in the 1700s, were bred for all sorts of different traits, and eventually returned to the Americas, becoming popular in North American gardens in the early 1800s.

With hundreds of cultivars available, these spectacular flowers continue to be one of the most popular garden annuals.

They have even been grown in space! In January 2016, astronauts shared photographs of zinnias blooming aboard the International Space Station.

The flowers were planted not only to beautify the station, but also provided opportunities for scientists to research how plants grow in microgravity.

Propagation

These flowers are easy to start directly from seed outdoors or can be propagated indoors to transplant out after the last frost. The roots are a bit sensitive to transplanting, so take extra care if you start seeds indoors.

From Seed

Sow seeds directly in the garden after the last frost, in a bed of well draining soil amended with compost.

Seeds should be planted 1/4 inch deep a few inches apart in rows or clumps. Keep moist until germination, which usually only takes about a week.

When seedlings are about three inches tall with a few true leaves, thin to six to 18 inches apart. Recommended spacing and mature spread varies depending on which cultivar you plant.

Read the instructions on your seed packet for specific spacing requirements.

From Seedlings

Roots are sensitive and prefer not to be disturbed, so if you live somewhere with a long growing season, this annual is best started outdoors.

In areas with shorter, cooler summers, transplanting can be a useful way to extend the season. It just needs to be done with care.

A close up horizontal image of seedlings growing in flats indoors ready to plant out into the garden.

It is useful to start seeds in two- to four-inch biodegradable containers like peat pots, or use seed blocks, to avoid disturbing the roots too much when transplanting them out.

That being said, I start zinnias indoors every year, often using plastic containers, and mine have always done just fine.

Start seeds about six weeks before the last frost, planting one-quarter inch deep in two- to four-inch pots filled with a well draining potting soil. Keep moist until germination occurs.

Keep an eye on the seedlings as they grow, watering when the soil appears or feels dry to the touch, and try not to let plants become rootbound.

Harden off for a week or so before planting out by moving seedlings outside for periods of increasing length each day, starting in a shady location and slowly moving to full sun.

Zinnias are frost sensitive, so it is important to wait until after the last frost to plant them out in their permanent location. They prefer minimum daytime temperatures of about 60°F, with 74-84°F being ideal.

How to Grow

Grow in a full sun location, in garden soil amended with organic matter. Zinnias are adaptable to a variety of soil conditions, but prefer well draining soil with a pH between 5.5 and 7.5.

A horizontal image of annual flowers growing in a mass planting in a field with hedging in the background.

Since they are prone to powdery mildew and other fungal conditions that thrive in areas with poor airflow, it is important to space your plants appropriately to provide good air circulation.

Allow for between six and 18 inches between plants, depending on the variety. Check the back of the seed packet for specifics.

A close up horizontal image of rows of seedlings planted out in the garden in spring.

Surround plants with at least two inches of straw or bark mulch to help with drainage, regulate soil temperature, and reduce weeds.

Young plants need plenty of water, about an inch per week until they are well established. Water deeply a few times a week in the absence of rain so the soil stays moist.

Mature zinnias are somewhat drought tolerant, and only need additional irrigation during periods of hot, dry weather.

Water in the early morning to allow foliage to fully dry in the heat of the day.

A close up horizontal image of a pink flower covered in droplets of water pictured on a soft focus background.

If possible, it is best to avoid overhead watering entirely, using a soaker hose instead to get water to penetrate deeper toward the roots while keeping the foliage dry. This will help reduce the risk of disease.

While they don’t need a lot of feeding, you can mix a light application of a slow release, well balanced organic fertilizer into the soil prior to planting.

You may also supplement with a monthly foliar feed to encourage bigger blooms. I recommend spraying foliage with compost tea or a well balanced organic fertilizer.

You can learn more about making and using compost tea in this guide.

Avoid high nitrogen fertilizers, which will increase foliage growth at the expense of flowering.

Growing Tips

  • Plant in full sun, in well draining soil amended with organic matter.
  • Space adequately to encourage airflow.
  • Apply mulch to improve drainage, regulate soil temperature, and reduce weeds.
  • Water young plants deeply, providing an inch of water per week.
  • Avoid overhead watering, and water in the early morning.

Maintenance

With proper care, zinnias can continue blooming for months! Deadheading spent blooms regularly will encourage new ones to form.

A close up horizontal image of annual flowers growing en masse in a flower border.

When they are young, you can choose to pinch the growing tips to encourage side branching, resulting in shorter, bushier plants with more flowers.

Keep in mind that this could delay flowering, especially in areas with short, cool summers.

These frost sensitive annuals will die after the first hard frost. If you want to save seeds for the following season, allow the last few flowers to mature fully, then collect and store the seeds in a brown paper bag.

You can learn more about how to collect flower seeds in our guide.

Cultivars to Select

The zinnia’s huge popularity in plant breeding over the last few centuries means there are many different cultivated varieties to choose from.

With a seemingly endless list of options, I find it quite easy to get lost while browsing seed catalogs for zinnias!

Flowers can take a few basic forms including single, double, and semi-double petal arrangements.

A close up horizontal image of a yellow flower growing in the garden pictured in bright sunshine with a red flower in soft focus in the background.

Single flowers consist of a single row of petals with a visible center.

Doubles have multiple rows with no visible center.

A close up horizontal image of a yellow double-petalled flower pictured on a soft focus background.

Semi-doubles, my personal favorite, have multiple rows of petals with a visible center.

A close up horizontal image of colorful semidouble zinnias growing in a garden border.
Photo by Heather Buckner.

Let’s take a look at a few of my favorite series and cultivars!

Chippendale Daisy

This fairly compact cultivar of Z. haageana is great for low borders or edges. It grows 12 to 18 inches in height with single petaled bicolored blooms of deep burgundy with bright gold rings.

A close up square image of bright red and yellow bicolored 'Chippendale Daisy' blooms pictured on a soft focus background.

‘Chippendale Daisy’

Seeds can be purchased from Eden Brothers in a variety of package sizes.

Crystal

An All-America Selections bedding plant winner in 1997 noted for being “highly tolerant of powdery mildew” and having an “excellent length of blooming season,” cultivars of Z. angustifolia from the Crystal™ series feature small, single-petaled daisy-like flowers that bloom all through the summer.

A close up square image of the tiny white flowers of Z. elegans Crystal series with foliage in soft focus in the background. To the bottom right of the frame is a white circular logo with text.

Crystal Series

The compact size of these eight- to ten-inch dwarfs makes them ideal for container growing either indoors or out.

You can find packs of 500 seeds available from True Leaf Market in white, orange, or yellow.

Dahlia Flowered Mix

This is an heirloom cultivar of Z. elegans developed in 1919. Long 40-inch stems are topped with stunning double flowers that are four to five inches in diameter.

A close up square image of the colorful blooms of double-flowered 'Dahlia Flowered' Z. elegans growing in the garden with a hedge in soft focus in the background.

‘Dahlia Flowered’

The ‘Dahlia Flowered’ mix provides a stunning blend of pinks, yellows, and oranges. These bright and vivid blooms look beautiful in mass plantings, borders, and mixed garden beds.

Seed packets of various sizes are available for purchase from Eden Brothers.

Dwarf Pepito Mix

If you are looking for something colorful to grow in containers, along borders, or in other small spaces, this semi-double dwarf variety of Z. elegans is a great choice.

A close up square image of a bunch of colorful cut flowers, Z. elegans dwarf 'Pepito' pictured on a soft focus background,

Dwarf ‘Pepito’

It matures to a conveniently manageable size, growing up to 10 inches tall, and produces a mix of pink, purple, red, yellow, and orange flowers with crimson centers.

Dwarf ‘Pepito’ Mix seeds can be purchased from Eden Brothers.

Pop Art Golden and Red

This unique bicolor cultivar of Z. elegans is a new variety, granted Approved Novelty status by Fleuroselect for its large double-petaled golden flowers with red flecks, reminiscent of the comic-style work of Roy Lichtenstein and other pop artists.

It grows 24 to 32 inches tall and spreads about a foot across. White and red or orange and red varieties of ‘Pop Art’ are also available.

A close up square image of a bright yellow flower with red accents pictured on a soft focus background. To the bottom right of the frame is a white circular logo with text.

‘Pop Art’

This variety is sensitive to cold, only able to withstand low temperatures down to around 60°F.

Packs of 500 seeds can be purchased from True Leaf Market.

Want More Options?

Be sure to take a look at our supplemental guide: “15 of the Best Zinnia Varieties to Grow in the Garden.”

Managing Pests and Disease

While these flowers are easy to grow, issues with pests and disease do crop up from time to time.

Just be sure to provide proper growing conditions and keep an occasional eye on your plants, and you shouldn’t have too much to worry about.

Insects

Zinnias are not significantly bothered by many insect pests, but damage can occur occasionally, especially when the weather is hot and dry.

Aphids

These small, often bright green insects can cause damage to foliage by sucking out the sap, leaving behind little holes. They can be found congregating in dense groupings on the undersides of leaves or along the stems.

A strong stream of water sprayed on foliage from the hose can typically remove aphids. Spray leaves early in the day so they have a chance to dry out.

Large infestations can be controlled with insecticidal soap or neem oil.

Read more about dealing with aphids in the garden here.

Caterpillars

There are several types of caterpillars that may be found feeding on foliage, including the oblique-banded leafroller (Choristoneura rosaceana), beet armyworm (Spodoptera exigua), variegated cutworm (Peridroma saucia), and cabbage looper (Trichoplusia ni).

In large numbers, caterpillars can defoliate the plant, destroying buds before they can bloom and stunting growth. Uncontrolled infestations may ultimately lead to plant death.

The best way to remove caterpillars is by handpicking them and drowning them in a bucket of soapy water.

You can also reduce the risk of infestation by weeding regularly. Providing ideal growing conditions will increase plant resiliency.

As a last resort, Bacillus thuringiensis can be used to control caterpillars. It should be applied starting early in the season and requires repeated applications, because the caterpillars need to ingest the Bt for it to work.

Japanese Beetles

These pesky flying beetles (Popillia japonica) are about a half an inch in length with metallic blue-green heads and copper backs.

They live in small groups, laying their eggs in the soil to overwinter underground. The adults emerge in summer to attack in groups, devouring foliage and flowers.

Plants subject to severe infestation can be skeletonized, with only the veins remaining.

Beetles can be hand picked and drowned in soapy water. An easy way to collect the beetles is by placing a drop cloth below the plant and shaking the foliage in the early morning when they are active.

Applying neem oil can be an effective long term strategy. The beetles ingest chemicals in the oil and pass them on to their eggs, causing the larvae to die before reaching adulthood.

Read more about dealing with Japanese beetles in the garden.

Spider Mites

Spider mites (Tetranychus urticae) are very small, and they appear in groups as tiny black dots. They can be found on stems and the undersides of foliage.

Like aphids, they feed on sap, creating small holes in the leaves. And they can likewise be removed with a strong spray of water in the early morning.

You can also pinch off affected foliage and destroy it to prevent further spread. Keep the area below plants free of debris, removing any fallen leaves and spent flowers.

A serious infestation can be addressed by treating plants with insecticidal soap or neem oil.

Since zinnias are such a good source of pollen and nectar for many beneficial insects, it is not recommended to use other chemical sprays.

If using an insecticidal soap, spray late in the evening when beneficial insects are not out. Cover the entire plant, including the undersides of leaves.

Disease

There are a few pathogens and fungal diseases that can be a problem for zinnias, particularly in humid conditions with poor air circulation.

For all of the following conditions, the best way to decrease the risk of disease is by reducing excessive moisture and providing adequate spacing. Always grow them in full sun in well draining soil, with plenty of space between each plant.

It is also good practice to avoid overhead watering, using drip irrigation when possible. These diseases can spread from one plant to another via splashing water.

Always remove and destroy affected plant parts when you see them. Keep an eye out for the following:

Alternaria Leaf Spot

This fungal disease, caused by the fungus Alternaria zinniae, produces small lesions that grow into dark concentric rings.

A close up horizontal image of a clump of zinnias infected with Alternaria fungi causing spots on the foliage and dying blooms.

It can cause foliage to become brittle and wilt.

Bacterial Leaf Spot

This bacterial pathogen (Xanthomonas spp.) appears as small and somewhat angular spots with a distinct yellow halo.

Cankers can develop on stems and flowers become misshapen, ultimately leading to wilt and decay.

Cercospora Leaf Spot

Caused by the fungus Cercospora zinniae, this disease exhibits similar symptoms to alternaria, but with larger reddish brown or purple spots that mostly affect lower, older leaves, eventually causing them to drop from the plant.

Sometimes both A. zinniae and C. zinniae may be present on the same leaf.

Powdery Mildew

This fungal disease, caused by Golovinomyces spadiceus, is particularly prevalent in humid areas.

It causes a white film to form on leaves that can quickly overtake the whole plant. Foliage will eventually turn yellow and drop, leading to a reduction in flowering as well.

A close up horizontal image of foliage affected by powdery mildew growing in the garden.

In addition to reducing the risk of disease by providing good airflow and watering at the base of plants, powdery mildew can be treated with an application of neem oil.

You can also try making a homemade organic spray by combining a tablespoon of baking soda with a tablespoon of horticultural oil in a gallon of water.

Spray the foliage whenever you notice signs of disease.

Best Uses

Zinnias are perfect for anywhere in the garden that you want to draw attention to their eye-catching blooms. And their long flowering season means you will be dazzled with a show of vibrant colors all through the summer.

A horizontal image of a garden scene with a variety of different flowers growing under trees with an arbor in the distance.
Photo by Heather Buckner.

They are wonderful additions to mixed planting flower beds and look beautiful when planted en masse.

A close up horizontal image of a white window box attached to a red house with orange flowers.

The more compact varieties make great border or container plants.

Humans are not the only fans of these eye-catching flowers. Pollinators love the large, bright blossoms. Grow zinnias to attract beneficial insects, butterflies, and hummingbirds!

A close up horizontal image of a Monarch butterfly feeding on a pink flower pictured in bright sunshine on a soft focus green background.

They also make lovely cut or dried flowers. They can last for weeks in a bouquet, adding dazzling color to any space.

To use for flower arrangements, cut the stems at an angle just above a bud node in the morning when flowers are opening. Strip off the leaves and set in a vase of warm water.

A horizontal image of a metal vase filled with brightly colored cut flowers set on a wooden box with a garden border in soft focus in the background.

You can easily dry the flowers by hanging them upside down in a bouquet in a well-ventilated area out of direct sunlight.

Quick Reference Growing Guide

Plant Type:Annual flowerFlower/Foliage Color:Various/green
Native to:MexicoMaintenance:Low
Hardiness (USDA Zone):3-10Tolerance:Heat, drought (established plants)
Season:Mid to late summerSoil Type:Any
Exposure:Full sunSoil pH:5.5-7.5
Time to Maturity:60-70 daysSoil Drainage:Well draining
Spacing:6-18 inches, depending on varietyAttracts:Bees, butterflies, hummingbirds
Planting Depth:1/4 inch (seeds)Companion Planting:Dahlias, marigolds, asters, nasturtiums
Height:Up to 4 feet (standard), 6-12 inches (dwarf)Uses:Mixed plantings, mass plantings, pollinator gardens, borders, containers, cut flowers
Spread:1-2 feetFamily:Asteraceae
Water Needs:ModerateGenus:Zinnia
Common Pests and Disease:Aphids, caterpillars, Japanese beetles, spider mites; Alternaria leaf spot, bacterial leaf spot, cercospora leaf spot, powdery mildewSpecies:Angustifolia, elegans, haageana

Grow a Rainbow

With magnificently colorful blossoms in almost every color of the rainbow, these impressive flowers are truly a must-grow annual.

A close up horizontal image of colorful zinnia flowers growing in the summer garden.

Plant some zinnias this season, grab a lounge chair, and watch the hummingbirds and butterflies flock to them!

What do you love most about growing zinnias? Share your stories and pictures in the comments section below!

For more beautiful annual flowers to grow in your garden this year, check out these guides next:

About Heather Buckner

Heather Buckner hails from amongst the glistening lakes of Minnesota, and now lives with her family on a beautiful homestead in the Vermont Mountains. She holds a bachelor of science degree in environmental science from Tufts University, and has traveled and worked in many roles in conservation and environmental advocacy, including creating and managing programs based around resource conservation, organic gardening, food security, and building leadership skills. Heather is a certified permaculture designer and student herbalist. She is also a fanatical gardener, and enjoys spending as much time covered in dirt as possible!

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Patty Combs
Patty Combs (@guest_12767)
3 months ago

Why do my zinnias have more leaves than flowers?

Allison Sidhu
Allison Sidhu (@allison-sidhu)
Admin
Noble Member
Reply to  Patty Combs
3 months ago

Sun exposure and/or fertilizer could be the culprits here. Zinnias love lots of sun, and applications of nitrogen-heavy fertilizer can cause plants to put more energy into foliage production than reproductive bud and flower growth.