Zinnias are colorful annual summer flowers that add bright colors to your yard or garden from early summer through late fall. Zinnias are members of the Asteraceae family, they have a single flower head situated on top of a step with dark green clasping leaves on each side.
These flowers have a lengthy, sturdy stem, which make them great for cutting.
Historically, Zinnias were primarily used as cut flowers;1 however, today it’s most common to see them planted in yards and gardens as ornamental flowers.
They’re beautiful, easy to grow, and attract a wide range of pollinators including several types of butterflies and even hummingbirds. There are several different species; however, Zinnia elegans is the most common and it’s almost exclusively cultivated for garden use.
Nevertheless, with several different hybrids, gardeners can get the best mix of colors and sizes. The flower is named after an accomplished German botanist named Johann Gottfried Zinn who discovered the flowers and brought them back to Europe in the 1700s.2
This complete guide explains everything you need to know about identifying and planting Zinnias in your own backyard.
How To Identify Zinnia
Wondering how to identify Zinnia or Interested in more Zinnia facts? You can easily spot a Zinnia by its oblong shaped-leaves and bright clusters of flowers.1
Below, we’ll tell you all about how to identify a Zinnia flower by its leaves, flowers, and seeds as well as how to grow and care for this beautiful plant.
Zinnia Leaves
Zinnias can easily be identified by their oppositely arranged clasping leaves with entire margins. They’re oblong or ovate in shape, they have no visible petioles, and they can grow to be up to 3 inches long.3
They are slightly hairy, rough in texture, and dark green in color, and you might also notice their prominent veins.3 Understanding how normal, healthy Zinnia leaves are supposed to look is helpful when it comes to diagnosing disease, which we’ll review in more detail below.
Zinnia Flowers
Zinnia’s blossoms are its most attractive and popular feature. These plants bloom bright, showy, solitary flowerheads, and Zinnia colors include red, purple, yellow, orange, white, red, green, and pink flowers.
They consist of a collection of ray florets on-top of disc florets connected at the center.1 There are anywhere from 7 to 20 rays per flower.1
They bloom in late spring and stick around throughout the entire summer.1 The flowers may be a darker shade when they first bloom and gradually lighten-up over the following weeks and months.
They might begin to fade by the end of the season.4 Flowerheads can have a diameter between 1 and 3 inches, and the size varies depending on the species.1
Most species of Zinnia flowers have three primary forms:5
- Single-flowered Zinnias: One row of petals and a visible flower center
- Double-flowered Zinnias: Multiple rows of petals, but no visible flower center
- Semi Double-flowered Zinnias: Multiple rows of petals and a visible flower center
Zinnia Seeds
Zinnia seeds are small, plump, firm, and pointy on one end.6 They also have a ridge on one side.
The seeds are usually found in the flower heads of Zinnia plants once the petals fall off. Zinnia seeds also have a good shelf life, and they can actually be viable for several years when properly stored.
Seeds should be sown in May or June for best results and germination takes anywhere from 8 to 10 days when planted in the right climate and soil conditions.6
Types of Zinnias (Z. elegans and Others)
There are 22 different species of Zinnias and hundreds of cultivars and hybrids.7 Below are some of the most common Zinnia varieties you’ll encounter:
Flowerheads are usually about 2 inches across, and this species is known to have some big blooms. While they mostly bloom bright colors, Z. elegans can also produce some of the most beautiful types of white flowers.
This species is what you’ll typically find in most garden stores around the United States.
(Image: Botswanabugs13)
4. Zinnia peruviana
Z. peruviana is a quick-growing subtropical variety that usually blooms red, orange, deep pink, or purple flowers. Zinnia peruviana grows to about 3 feet tall and is more capable of withstanding hot climates.8
It’s native to Southwestern US, Mexico, Venezuela, and Argentina.8
The Best Growing Conditions for Zinnia Plant
The best growing conditions for Zinnia plants are similar to most other annual flowers. Here are some planting tips for Zinnias:
Zinnias are “prolific bloomers” all summer long, but in order for them to achieve the best blooms, they need the best possible growing conditions. Zinnias prefer full sun and well-drained soil.
Exactly how much sunlight does Zinnia need each day? Somewhere between six and eight hours1.
They prefer garden beds, so container gardening isn’t the best option. They’re also able to grow rapidly.
Soil temperatures should be around 70 degrees (late spring/early summer), and remember, Zinnias are very sensitive to the cold, so be careful not to plant them until you’re sure the last frost has passed. Zinnias prefer a day-time temperature of between 74° and 84°F, and will grow so long as the temperature does not dip below 60°F.1
On the other side, Zinnias do not like it when heat consistently exceeds 84°F, and they can die prematurely if temperatures remain over 100° for several days or weeks. Wondering how far apart to plant Zinnia?
When it comes to Zinnia spacing, seeds should be placed a few inches apart to prevent the spread of disease and allow for air circulation.
Zinnias are not hardy in small subsections within the northernmost points of the United States as well as small pockets of Southern California or Southern Florida where summer temperatures are too hot. 2 to 11 are the best U.S. growing zones for Zinnia.
Where to grow the plant on your property ultimately comes down to sun exposure and soil quality.1
Wondering how long it takes to grow Zinnias? From seed to full bloom can take up to 2 months, but it may be faster under the right conditions.1
Growing a Zinnia From a Seed, Cutting and Seedling (Zinnia Sprouts)
Growing a Zinnia from a seed is the most effective way to get the best results. When seeds are sown in the right conditions, plants will begin to grow within 8 to 10 days.
Watering needs for Zinnia plants mirror most other annuals. Consistently maintaining most soil for the first two to four weeks is essential, and once established, Zinnias need watered about 3 times each week.6
Zinnias can also be started indoors. This should be done no more than 6 weeks from your intended planting date.
Seeds should be kept moist and planted ¼ inch deep.6 They should also be covered with black plastic to eliminate any light.
Indoor temperatures will need to be kept between 70° and 75° F. Seeds will germinate in 7 to 10 days.6
They can also be grown via cuttings, but this process takes about 3 to 4 weeks.
When growing from cuttings, you just need to remove 4 to 6 inches from the top of the plant and eliminate the leaves from the bottom portion of the cutting.
Then, place the cutting in water (make sure the entire bottom portion is submerged) until roots begin to grow, and then transplant it into soil.6
While growing from a cutting or a seedling is possible, Zinnias don’t love being transplanted, so this doesn’t always produce the best results. You’ll usually have better luck when growing from seeds.
Zinnia Care
Zinnia care is fairly simple. So long as Zinnias have a healthy supply of well-drained soil, receive adequate water, and are in a moderate climate, they don’t need much more in terms of care.
Zinnia
(Zinnia spp.)
- Characteristics: Bright showy solitary flower heads perched on top of stiff, hairy stems with oval leaves.
- Family: Asteraceae
- Genus: Zinnia
- Leaf: Oval or elliptical; grasping the step from opposite sides
- Seed: Plump, firm, tear-shaped; best sown in May or June
- Blossoms: Solitary flower heads in a wide range of bright colors born at the ends of branches
- Native Habitat: North America and South America
- Height: 1’ to 3’
- Canopy: Thin, sturdy stems hold solitary flower heads that can grow between 1 and 3 inch in diameter.
- Type: Annuals
- Native Growing Zone: Zones 2 - 11
After they bloom, they only need to be watered about 3 times each week. You can also lightly apply fertilizer as a way to maximize growth and get the best blooms.
Throughout the summer, you can cut older flowers as a way to promote new flowers to form.5
In addition to several diseases that we’ll cover below, Zinnias are also susceptible to pests. Aphids, spider mites, and whiteflies are common pests of the Zinnia.
Furthermore, eliminating pests is tricky, because insecticides could harm pollinators (bees and butterflies) that benefit from Zinnias. As a result, it’s only recommended that you use natural pest control for Zinnias.
Insecticidal soaps may be applied, but should only be used in the evening. You should also be careful to only spray the lower surfaces of the leaves, and avoid the flowers.
Do Zinnias Come Back Every Year?
Zinnias are annuals, which means they will die as soon as the fall’s first frost sets in. If you’d like to enjoy these beautiful flowers again next summer, you’ll need to plant new seeds next season.
(Image: Alicja (_Alicja_)15)
You can also allow the last flowers of the season to fully mature and scatter seeds, which may grow the following year.
Common Uses for Zinnia elegans
Yard beautification is one of the most common uses for Zinnia elegans. Due to their vibrant colors, Zinnias are primarily used in landscape gardening or as a garden flower.
They can be planted in large or small groups or used as a border plant. While they prefer to be planted, they can also survive in containers and on patios.
Because they’re highly attractive to pollinators, they’re a perfect flower to add to butterfly gardens. With their vibrant tones and summer-long blooms, they can add a visually appealing touch to any property.
If you’re looking to add plants that attract hummingbirds, these flowers are a great choice. They also attract dozens of types of butterflies and many types of bees.
Zinnia symbolism dates back hundreds of years. The Victorians were very fond of this flower and they wrote about it extensively.
The flower was frequently considered a symbol of affection, friendship, and tribute. Zinnias even make appearances in some of Shakespeare’s works.
Because of their bright blooming colors, the Aztecs used to refer to them as “plants hard on the eyes”.
How To Stop Zinnia Disease
Unfortunately, these plants are susceptible to a wide range of diseases. Providing adequate spacing between plants, ensuring your plants receive full sunlight, and avoiding overwatering are best practices for Zinnia disease prevention.
(Image: Denise Davis16)
Below are some of the most common fungal conditions that can impact your flowers:9
- Powdery Mildew: This is the most common Zinnia disease, and you’ll notice it when white spots develop on the leaves. The spots will appear more pronounced on hot days.
Powdery Mildew will affect the upper surfaces of the leaves at first before spreading. It’ll eventually cause the leaves to turn brown,9 and it can easily spread to other plants when flowers aren’t provided with adequate spacing.
If you notice powdery mildew, carefully remove the impacted leaves. You can also consider applying horticultural oil or potassium bicarbonate to the infected sections. - Blight: If you notice small, reddish-brown spots with a touch of gray in the middle, this could be a sign of blight.9 These spots will gradually get larger and may even begin to drive the formation of dark brown cankers.
If you notice signs of blight, eliminate the impacted leaves and try to add some fertilizer and extra water to improve the health of the plant. - Botrytis Blight: This fungus causes flowers to develop brown spots with a “target-like” appearance and fuzzy masses.9 Stems may also develop cankers.
Remove impacted leaves as soon as you notice signs. Ensure adequate spacing between plants and avoid overwatering.
Try to ensure flowers are receiving good air circulation. - Cercospora Leaf Spot: It’s much less common than powdery mildew and other diseases, but Cercospora leaf spot produces reddish purple spots with large white centers. The spots are clustered together, and they’ll quickly kill the leaves.
Zinnia plants can be afflicted by diseases from various microorganisms such as Bacterial leaf spot, which results in brown leaf spots from bacterial infection, aster yellows that severely distort leaves due to phytoplasma, and Foliar nematodes that create vein-delimited angular spots caused by nematode worms.
However, by paying attention to their needs, these lovely flowers will provide a host of benefits for your outdoors.
Frequently Asked Questions About Zinnia
What Is the Ideal Zinnia Growing Zone?
The plant is hardy in US growing zones 2 – 11. So long as Zinnias have moderate air temperatures, well-drained soil, full sunlight, and regular watering, the plant will thrive.
What Are Some Companion Plants for Growing Zinnia Flowers?
Choose plants with similar light requirements, watering needs, and bloom times to achieve the optimal look in your garden. Marigolds, Cosmos, Salvia, Verbena, and Sweet Alyssum are all good companion plants for Zinnias.
Are Zinnias Perennials?
No, Zinnias are annuals which mean they bloom once and won’t return the next year. To enjoy these flowers next season, you’ll need to plant seeds again in the spring.
Can You Tell Me When To Plant Zinnia Seeds?
Seeds can be planted as soon as the last frost has fallen, and they’ll take between 8 and 10 days to germinate.
Can You Tell Me How To Plant Zinnia Seeds?
Zinnia seeds should be planted a few inches apart and about ¼ inch deep into well-drained soil in an area with full sunlight. The soil should be watered frequently until plants are established.
Can You Tell Me How To Save Zinnia Seeds?
If you have extra seeds that you’d like to save for next season, place them in an envelope and then put the envelope in a glass jar. Store it in a cool, dark location (no sun is important).
What Do Zinnia Seeds Look Like?
Zinnia seeds are small, plump, and shaped like tear drops with a ridge on one-side and one pointy end.
I’m Wondering How To Harvest Zinnia Seeds for Next Season?
Take a dried flower and gently tap the seed head to release seeds. You could also attempt to carefully pull the seed head apart, which will allow the seeds to fall out.
What Is the Zinnia Growth Rate?
Once seeds are planted, Zinnias will grow very quickly. Total seed to flower time is about 2 months.
Learn More About Zinnia
Blanket Flower Guide: Growing Blanket Flowers, Types, Care Tips (ID Charts)
Butterfly Pea Vine Flower: How To Identify and Grow Types of Blue Pea
Growing Foxglove Plant Guide: Growing Zones, Care Tips, Foxglove Flowers
Delphinium Flower Colors and Types: How to Grow Delphinium, Care Tips
Dahlia Flower: How To Grow Dahlias, Planting and Care Tips, Types of Dahlias
Lily of the Valley Flower: Planting Lily of the Valleys, Care Tips, Growing Zones
References
1NC State Extension. (2024). Zinnia elegans. North Carolina Extension Gardener Plant Toolbox. Retrieved January 24, 2024, from <https://plants.ces.ncsu.edu/plants/zinnia-elegans/>
2Nardozzi, C. (2024). All About Zinnias. American Meadows. Retrieved January 24, 2024, from <https://www.americanmeadows.com/content/wildflower-seeds/zinnia-flower-seeds/all-about-zinnias>
3University of Florida. (2024). Plant Identification Learning Module: Zinnia (Zinnia elegans). Plant Florida Identification. Retrieved January 24, 2024, from <https://gardeningsolutions.ifas.ufl.edu/mastergardener/outreach/plant_id/flowers_indoor/zinnia.html.>
4Roberta. (2015, April 2). Zinnias: Flower Cycles And Parts. Growing With Science Blog. Retrieved January 24, 2024, from <https://blog.growingwithscience.com/2015/04/zinnias-flower-cycles-and-parts/>
5Boeckmann, C. (2024, February 14). How To Plant, Grow, And Care For Zinnia Flowers. Almanac. Retrieved January 24, 2024, from <https://www.almanac.com/plant/zinnias>
6University of Minnesota Extension. (2022). Zinnia. University of Minnesota Extension. Retrieved January 24, 2024, from <https://extension.umn.edu/flowers/zinnia>
7Grant, A. (2021, October 10). Choosing Zinnia Varieties – What Are The Different Kinds Of Zinnia? Gardeningknowhow. Retrieved January 24, 2024, from <https://www.gardeningknowhow.com/ornamental/flowers/zinnia/choosing-zinnia-varieties>
8Gardenia. (2024). Zinnia peruviana (Peruvian Zinnia). Gardenia. Retrieved January 24, 2024, from <https://www.gardenia.net/plant/zinnia-peruviana>
9State of Connecticut. (2024). Zinnia (Zinnia). The Connecticut Agricultural Experimentation Station. Retrieved January 24, 2024, from <https://portal.ct.gov/CAES/Plant-Pest-Handbook/pphZ/Zinnia-Zinnia>
10Species Information Image: Pink Flower With Green Leaves Photo by Kiriakos Verros. (2020, December 31) / Unsplash License. Cropped and added text, shape, and background elements. Unsplash. Retrieved March 1, 2024, from <https://unsplash.com/photos/pink-flower-with-green-leaves-_-jtBrFI9YA>
11Elegant Zinnia Photo by Ian Wolfe. (2022, June 23) / CC0 1.0 DEED | CC0 1.0 Universal. Cropped and Resized. iNaturalist. Retrieved March 1, 2024, from <https://www.inaturalist.org/photos/208519706>
12Zinnia Haageana Photo by Oscar Alejandro Morales Juárez. (2017, August 17) / CC BY-SA 4.0 DEED | Attribution-ShareAlike 4.0 International. Resized. iNaturalist. Retrieved March 1, 2024, from <https://www.inaturalist.org/photos/9977649>
13Peruvian Zinnia Photo by Botswanabugs. (2021, April 20) / CC0 1.0 DEED | CC0 1.0 Universal. Resized. iNaturalist. Retrieved March 1, 2024, from <https://www.inaturalist.org/photos/122137904>
14Zinnia Angustifolia Photo by Alexis López Hernández. ( August 20, 2020 ) / CC BY 4.0 DEED | Attribution 4.0 International. Resized. iNaturalist. Retrieved March 1, 2024, from <https://www.inaturalist.org/photos/92078521>
15Zinnia Flowers Summer Garden Photo by Alicja (_Alicja_). (2018, July 6) / Pixabay Content License. Resized. Pixabay. Retrieved March 1, 2024, from <https://pixabay.com/photos/zinnia-flowers-summer-garden-3518967/>
16Photos of Zinnia Flowers by Denise Davis