The colorful blooms of zinnias are typically thought of as annuals, but you can also grow perennial zinnias. In fact, if you are a gardener in the American Southwest, perennial zinnias are arguably one of the very best choices for your landscape.
In this post, you will learn everything you need to know about what types of zinnias are perennials, how to plant them, and how you can maintain them so they return to bloom each year. Use the advanced jump below to jump to any subtopic, or read on for the full zinnias growing guide.
Jump to:
- What Are Zinnias?
- Are Zinnias Perennials or Annuals?
- What Types of Zinnias are Perennials?
- Zinnia Basics
- Where Do Zinnias Grow?
- Why Grow Zinnias?
- When Do Zinnias Bloom?
- How Long Do Zinnias Bloom?
- When to Plant Zinnias
- Ideal Growing Conditions for Zinnias
- How to Plant Zinnias
- How to Propagate Zinnias
- How to Care for Zinnias
- Recommended Planting Combinations for Zinnia
- Zinnia Landscaping Ideas
- Recommended Zinnia Varieties
- Frequently Asked Questions About Growing Zinnias
- Where to Buy Zinnias
What Are Zinnias?
Let’s begin with the basics of what you should know. Zinnias are flowering plants that belong to the genus Zinnia in the family Asteraceae. As you probably guessed, that is the aster family.
While zinnia blooms can vary in appearance, the classic zinnia features densely packed, tiny petals for a slightly rounded look. The hues of most zinnias are warm, typically yellows, oranges, and pinks.
Are Zinnias Perennials or Annuals?
The majority of zinnias are true annuals, which live for only one season, regardless of climate zone. But there are some types of perennial zinnias. As gardeners in desert regions become more eco-conscious, perennial zinnias are becoming more popular.
What Types of Zinnias are Perennials?
Here are a few that can bring beauty to your native garden each year:
Zinnia grandiflora
The type of zinnia that most people think of when they picture perennial zinnia is this species, commonly referred to as “wild zinnia,” “Rocky Mountain zinnia,” or “prairie zinnia.”
It produces a dense abundance of golden blooms and features a mounding growth habit. The flowers being appearing in mid-summer and continue until the first frost.
USDA writes, “The wild zinnia is becoming more appreciated as a garden plant, and it is now found on several lists of recommended water-wise plants for western gardeners. An internet search using the scientific name, Zinnia grandiflora, will lead you to several sources of plants and seeds. It is a sturdy spreading perennial once established, but it will not break dormancy or grow until early summer heat arrives, so be patient.”
Zinnia angustifolia
This type of zinnia is known as “creeping zinnia.” We have seen it classified as both an annual and a perennial, so whether it returns each year likely depends on where you plant it and how you care for it. You can find it growing throughout Mexico and the US Southwest.
Starting in June, it produces beautiful blooms in yellow, white, orange, pink, or red that look similar to daisies. The display continues until the first frost.
Zinnia acerosa
This type of zinnia goes by the common names “desert zinnia,” “white zinnia,” “wild zinnia,” and “spinyleaf zinnia.”
As you might guess, the reason for the name “desert zinnia” is because this perennial zinnia is common in desert regions. You can find it throughout the American Southwest and also in parts of Mexico.
Most types of desert zinnia produce white blooms with yellow centers. But we have seen desert zinnias that produce eye-catching blooms with deep golden petals and red centers as well.
Other Zinnias
There are some additional types of perennial zinnias as well, but they do not have as much ornamental value as the ones we just shared with you.
As for the annual cultivars, you should not shy away from those too much. Despite the fact that they only live for a year, you can let them go to seed and enjoy new zinnias each year.
Zinnia Basics
| Zones: | 2-11 (depends on type) |
| Blooming season: | Summer through fall |
| Expected height: | Up to 4 feet (depends on type) |
| Soil: | Well-draining |
| Sun: | Full sun |
Where Do Zinnias Grow?
If you are a gardener in the US or Mexico, one of the most noteworthy things to you about zinnias is going to be their native range.
Zinnias are native to Mexico, the American Southwest, and parts of South America. You will find them growing naturally in scrublands and grasslands. The largest center of diversity for zinnias is in Mexico.
Since zinnias can be grown in zones 2-11, they have been cultivated around the world. But if you are located in their native range, they are truly an ideal fit for your region—especially the perennial zinnias that can flourish happily in your dry conditions for years.
Why Grow Zinnias?
Hands down, zinnias are some of the best plants for beginner gardeners and advanced gardeners alike, especially in the Southwest. Here are a few of the benefits of these plants that make them such an amazing addition to your garden bed.
• Native plants: It can be good for the local ecology if you grow plants that are native to your region. Zinnias are native to states in the Southwest and will not cause problems for other plants or wildlife. In fact, they play useful roles in ecology, as we will discuss below.
• Attractive to pollinators: Butterflies, hummingbirds, and bees all are known to seek out zinnia plants.
• Rapidly-spreading groundcover: Despite the fact that zinnias are not invasive, they do spread quickly with little to no effort on your part. So, if you are in search of a groundcover that can swiftly transform your landscape, zinnia is an excellent option.
• Drought-resistant: If you need a plant that can make it through hot summers in an arid location, perennial zinnia will make your life easy.
• Long bloom period: When you grow zinnias in your garden, you can look forward to many months of blooms.
• Great for planting at elevation: Zinnias are considered to be one of the top plants for gardeners who live at elevation (i.e., high deserts or even the Rockies).
• Exceptionally hardy: Perennial zinnias are some of the toughest ornamental flowering plants you can grow. NC State Extension writes, “This adaptive plant is deemed to be rugged and durable, existing in conditions characterized by rocky-sandy soils, severe heat, strong winds, and cold temperatures. In the garden, it can flourish in typically difficult locations such as south-facing slopes and along hot driveways. With adequate and consistent moisture, it will lose its brittle quality and will appear fuller with brighter blossoms.”
• Deer and rabbit resistant: Deer and rabbits do not generally eat perennial zinnias.
• Practically disease- and pest-free: It is unlikely to have problems with pests and diseases when you are growing perennial zinnias. In fact, they may even have pest-prevention benefits for other plants (more on that in the section on companion planting).
• Combat soil erosion on slopes: Zinnia can help to provide some degree of stabilization for loose soils on slopes, reducing the effects of wind erosion. This can help you to maintain the shape of your landscape and provide other plants with a more conductive environment.
• Ridiculously low maintenance: We cannot think of another choice for gardeners that requires as little work. You barely need to water or prune these plants, and you do not have to worry about staking them. If you mostly just leave them alone, they should grow quite happily in your garden.
So, you can see how planting some perennial zinnias can provide you with a ton of amazing benefits for your garden all at once.
When Do Zinnias Bloom?
Zinnias bloom in summer and fall.
How Long Do Zinnias Bloom?
Zinnias can bloom continuously for months.
When to Plant Zinnias
Unlike a lot of other plants, zinnias are usually grown from seed primarily rather than from nursery plants. Spring or fall are ideal seasons for sowing those seeds.
Ideal Growing Conditions for Zinnias
Growing perennial zinnia flowers successfully is really easy if you have the right conditions for them. Let’s talk about the sun, soil, and water requirements for these blooms.
How Much Sun Do Zinnias Need?
Zinnias typically prefer full sun, but in some locations, they may also appreciate partial shade.
What Type of Soil is Right for Zinnias?
Fertile, well-drained soil is an excellent choice for zinnia annual flowers. But for perennial zinnias, there is definitely such a thing as too much richness. Moderate and poor soils may even result in happier plants. The pH of the soil should be on the alkaline side.
The soil can be relatively moist or dry, but it should not be allowed to be waterlogged. Good drainage is essential.
Does it need to be loose? If you want the plants to spread effectively, then yes. But if you actually want to contain them, you will find them easier to manage in heavy soils.
How Much Water Do Zinnias Need?
Now you know zinnias are flexible about soil type and grow best in a sunny spot. But how much water do they require?
For healthy plants, some water is needed, but it may be provided by precipitation, depending on where you live.
Annual zinnias need about an inch of water per week. We have seen some sources say that perennial zinnias do not require watering beyond what they receive from Mother Nature unless serious drought conditions set in. Keep an eye on your zinnias, and do your best not to under or overwater them.
How to Plant Zinnias
When planting zinnias, you have two options: plant them in your flower beds, or plant them in container gardens.
Ground Planting
To plant zinnias in the ground, you need to start by identifying a good site in your garden. Then, you may want to prep the soil by amending it with compost, especially if you need to improve drainage (but take care that you do not make the soil too rich). You can then sow your seeds.
Container Planting
Zinnias can grow just fine in containers—which may be a good option if you do not want them to spread. Just make sure that the pots you pick out have drainage holes in the bottoms.
How to Propagate Zinnias
There are three ways you can propagate zinnias: from seeds, cuttings, or divisions.
Starting Zinnias from Seed
The most common way to grow zinnias is from seeds. You can easily find packets of seeds for annual zinnias. It may take a bit more effort to find perennial zinnia seeds. NC State Extension says, “The seeds may be difficult to source as they are easily broken when cleaned by a machine.”
Nevertheless, at the time of this writing, we were able to find seeds for perennial zinnias instantly with a single online search. So, thanks to the power of the internet, you should not have any major issues coming by perennial zinnia seeds. If they grow wild in your area, you can also harvest seeds from existing local zinnias.
Although your zinnias should spread on their own, you can also cultivate future zinnia plants from your existing zinnia perennials by harvesting their seeds.
Once you have your perennial zinnia seeds, here is how you can plant them:
1. In mid-spring or any time after during summer or early fall, sow your seeds on the surface of the soil. Ideally, the temperature of the soil should be in the range of 65 to 70 degrees Fahrenheit.
2. Cover the seeds with a very thin layer of soil; you should not bury them deep.
3. Water as needed while waiting for the seeds to germinate, which can take anywhere from 10 to 30 days.
If you prefer, you can start the seeds indoors 6-8 weeks before you expect the final frost of the year. After the last frost, if the seedlings are ready, you can harden them and then plant them outdoors. There should be about 6-8” of space between each of them.
Don’t know what “hardening” is? It is the process of gradually getting a plant that has been living indoors used to living outdoors. You just take the seedlings outside for short periods of time, increasing the duration with each. Then you move them outdoors full-time.
Starting Zinnias from Cuttings
Another way to propagate your zinnias is by taking cuttings. Follow these instructions:
1. Take cuttings from your zinnias that measure several inches, cutting just below a leaf node for each.
2. Remove the bottom leaves from the cuttings, but leave the top leaves alone.
3. Fill a clear vase or jar with room-temperature water.
4. Insert the cuttings into the vase or jar. Be sure that the leaves are not touching the water.
5. Find a spot where your cuttings can receive indirect light. They should be kept at about 75 degrees Fahrenheit.
6. Pour out the water and replace it each day so that you do not promote disease.
7. After about 5-10 days, you should notice roots forming. Continue to replace the water daily while the roots keep developing for a few more days.
8. Transplant the cuttings into containers or your flower beds.
How to Divide Zinnias
Annual zinnias do not require division, but you can divide perennial zinnias. You may want to do this if your clumps are not blooming as abundantly as usual or if you just want to create more zinnia plants.
You can follow the standard directions for dividing perennials:
1. Using a shovel, dig in a circle around the clump of zinnia you wish to divide. Then, push the shovel under the clump so you can pry it out of the ground.
2. Wipe away the excess soil.
3. Carefully pry apart the clump to create two or more divisions.
4. Dig holes for the newly divided zinnias and transplant them. Backfill the soil and water well.
How to Care for Zinnias
What do you need to know about caring for zinnias? Let’s discuss instructions for fertilizing, mulching, staking, and pruning these popular plants.
How to Fertilize Zinnias
Although annual zinnias are heavy feeders (give them a balanced fertilizer), perennial zinnias usually do not require fertilizer. That is awesome, right? It is one less thing to worry about.
How to Mulch Zinnias
While we have seen multiple sources recommend mulch for perennial zinnias, there seems to be some disagreement regarding whether it should be organic or inorganic mulch. You might want to experiment with different mulch materials to figure out what your zinnias prefer.
How to Stake Zinnias
Some types of zinnias grow tall enough that they can benefit from staking. But the perennial forms are usually pretty low to the ground and probably will not need any support.
How to Prune Zinnias
Zinnia pruning is quite easy and mostly consists of deadheading and minimal pruning during the growing season.
How to Deadhead Zinnias
You can deadhead your zinnias simply by pinching off the spent blooms when you see them. This will encourage your plants to keep producing fresh blooms throughout the growing season.
If your zinnias are taking on a leggy, unkempt appearance, you can do a little additional pruning to improve their look.
When to Cut Back Zinnias
Can you trim back zinnia like other perennials? Yes. Mountain States Wholesale Nursery says, “Since the plant goes deciduous, winter is an ideal time to trim plants back.”
Are Zinnias Vulnerable to Diseases or Pests?
Usually, in this section, we start listing diseases, insects, and other pests and problems for perennials. But with perennial zinnias, every source we looked at just said that they are pretty much disease- and pest-free. Japanese beetles are probably the biggest pests for annual zinnias.
Bear in mind that fungal diseases can still take hold if plants are allowed to stand in soggy soil and/or do not have enough air circulation.
Recommended Planting Combinations for Zinnia
Zinnias are actually a frequently recommended companion plant for a wide range of scenarios, owing to their ability to attract pollinators while reducing the presence of whiteflies. So, you can consider planting zinnias anywhere you want to drive these pests away.
Zinnia Landscaping Ideas
Here are some ways you can use these beautiful flowers in your landscape.
• Native prairie garden: If you have a prairie garden you want to fill with native blooms, then it is hard to beat zinnias. Even though they spread, they are not invasive.
• Rock garden: Zinnias will grow with no issues in rocky and sandy soils, so they are an excellent option if you have a desert landscape that could use some color and life.
• Pollinator garden: Plant these summer flowers in your pollinator garden to attract friendly guests.
• Groundcover: Perennial zinnia makes for a gorgeous and effective groundcover, filling in empty patches with vibrant color.
• Sunny border: You can plant annual or perennial zinnia to create borders along flower beds or walkways.
• Hellstrip: In landscaping terminology, a “hellstrip” is a little narrow plot between a sidewalk and the street. Hemmed in on both sides by these heat/light-reflecting surfaces, it can be an uninviting growing zone. But zinnias can grow well there.
Recommended Zinnia Varieties
If you want to grow perennial zinnias, our top recommendations are Zinnia grandiflora, Zinnia angustifolia, and Zinnia acerosa.
We won’t get into annual zinnias in this post but suffice to say there are dozens of amazing cultivars in a wide abundance of hues, so there are tons of options to enhance your landscape.
Frequently Asked Questions About Growing Zinnias
Let’s wrap up this post with answers to a few commonly asked questions about zinnias.
There are no major pests for zinnias. Japanese beetles can be a problem, but if something is eating yours, you will need to pay close attention to find out what is going on.
Zinnias are classified as non-toxic to dogs, cats, and horses. That is awesome news if you have a pet!
If you plant perennial zinnias, then yes, they will come back every year. Technically, the annuals will probably fool you into thinking they do as well since they self-seed.
Yes, zinnias do bloom all summer if they are healthy and growing in the right conditions. This is one of the reasons why they are so beloved by gardeners in the American Southwest and beyond.
Yes, zinnias are effective self-seeders, so if you let them go to seed, then they will spread quickly. Perennial zinnias also spread through their clumps.
Where to Buy Zinnias
If you want to shop for zinnias, we suggest that you do it online. Not only will you find the best selection of annual zinnias that way, but you will also find it much easier to shop for seeds for perennial zinnias that will return to grace your garden every year.
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