Growing Plants

Do Zinnias Reseed Themselves Every Year? Growing & Caring Guide

The colorful, vivid zinnia bushes in the backyard make any gardeners can’t help but want more. The thing is, do zinnias self seed? Or do you have to replant them all after the flowering season?

My post will address this concern along with information about the plant’s growing method, the guidelines on caring, harvesting, saving, and other requirements.

Keep scrolling down for further details!

About Zinnia 

do zinnias self seed

Zinnia is a genius of the Heliantheae tribe. It is native to the dry grassland and shrubland that stretches over a large area from the Southwestern United States to Mexico.

Zinnia is an annual plant with a height ranging from 8 inches to even 3 feet.

You can easily identify its species with others thanks to their beautiful flowers with various vibrant colors, which are made of 12 long-stemmed petals.

Its stems form an upright shape and spread over the ground’s surface, like a baby’s scrawling. The leaves are often opposite and sessile, coming in various shapes, like linear or ovate.

Their colors are also diverse, from light, pale to medium green, depending on the chloroplasts’ pigment.

Zinnia is indeed gorgeous, especially under bright sunlight. Besides its beauty, this plant also gives off a pleasant scent, attracting many pollinators and insects.

So, be careful when coming close to adore this species if you don’t want to get bitten.

It is also easy to grow, yet you have to meet a few requirements before undertaking the process. So what are they, and how to cultivate Zinnias? Stay tuned!

Do Zinnias Self Seed?

Yes. If you master growing Zinnias and prepare good conditions for their growth, including the soil and watering, their seeds will germinate when dropped on the nearby ground.

More specifically, when a Zinnia seed drops into the soil, it will absorb the nutrients and get water normally, just like hibiscus seeds

The seed will grow, and you will notice its first spring after a few months. That’s why many gardeners favor Zinnia because of its re-germinating function.

How To Grow Zinnias From Seed?

will zinnias reseed themselves

Here are detailed instructions on growing a Zinnia plant that you should pay close attention to.

Choose The Site

Zinnias are easy to plant, as they are not picky about the soil. They can grow in some soil types of bad quality, but it is highly recommended to choose well-drained soil to facilitate their mature growth.

Indeed, soils that are waterlogged can result in many disease concerns, wreaking havoc on the seedlings’ health. Clay or heavy soils are unfavorable due to their weakened drainage qualities.

To amend this situation, it would be best to add some compost or other organic supplements.

After selecting the suitable soil, you must focus on the planting site. This location should be under direct sunlight for 6 to 8 hours each day.

Lower sun exposure could not make Zinnia bloom properly, even inducing it to be spindly or stretched.

Select A Proper Timing

Zinnias favor hot climates, so the optimal season for their growth is summer when the warm weather sets in.

A surprising fact is that this plant is quite susceptible to low temperatures, and the frost could result in its sudden death.

That’s why the ideal temperature should range from 70 degrees Fahrenheit.

If you left it to thrive in an environment whose temperatures are lower than 70ºF, it would be your bad mistake, causing it to stretch gradually before succumbing to the harsh conditions.

The Step-By-Step Process

Below are two methods you can apply to sow Zinnias’ seeds, both indoors and outdoors.

Grow The Zinnia Plant Indoors

  • Step 1: Choose the seed of your favorite Zinnia plant type, as there are numerous species belonging to the Zinni family.
  • Step 2: Look for a small pot made of plastic, which is more durable, and you don’t need to worry about accidentally falling it down. Prepare high-quality compost as well.
  • Step 3: Add soil to the pot, and bury the seed a few inches deep. It is advisable to place it on the damp compost. As regards the ratio, allow only eight seeds with distances of 9 centimeters.
  • Step 4: Cover the seeds with a thin layer of potting mixture or vermiculite after firmly placing them. Using horticultural sand is also recommended to prevent their roots from being rotten.
  • Step 5: You can use a plastic bag to cover the pot to heighten the moisture level. But it seems unnecessary to Zinnias, so this step is optional.
  • Step 6: Water the pot of seeds frequently and always keep an eye on their growth to avert worse scenarios. Don’t water them too much because excess water is unable to drain to the full.
  • Step 7: When seedlings form two leaf pairs, prick them out and leave them to thrive.

If you live in a cold climate, you must take close notice of all frost risks, harden the leaves off, and plant out 30 centimeters apart when winter is over.

Grow The Zinnia Plant Outdoors

  • Step 1: Pick a suitable Zinnia seed that you are going to plant.
  • Step 2: Pull a rock over the ground’s surface to get rid of hard stones with the purpose of creating a crumbly and fine consistency.
  • Step 3: Make a straight line with the assistance of a taut string. Don’t forget to take a shadow drill out before burying your plant seeds.
  • Step 4: Begin to sow the Zinnias’ seeds along the line. Ensure that their distances are from 10 to 15 centimeters apart. After burying them down, use your hand to cover them with soil gently.
  • Step 5: Prepare a potting mixture, including sand, perlite, and peat moss. It is a good facilitator to your Zinnias’ growth. Adding compost to the soil is advisable.
  • Step 6: Water the seeds and mark this area with a label or a warning sign. Always keep the soil moist to avert the saturation phenomenon.
  • Step 7: When the seedlings start to form their first sprout, cover them with a cloche. And thin them until you see some pairs of leaves.

Remember to eradicate the weeds carefully, as their invasion is a menace to Zinnias’ health if left unchecked.

What Is The Best Zinnia Plant Care Guide?

does zinnia self seed

Given several factors, the following is an all-inclusive guidance on caring for your Zinnia plant.


As mentioned earlier, you should choose the location for your Zinnia, which is directly exposed to the sun and receives about 6 to 8 hours of sunlight.

Zinnia loves full sun, so if you want to create the best environment for it to flourish, sunlight is one of the determining factors you must acknowledge first.


Right from its establishment, this plant’s capacity for drought-tolerating is excellent, yet it still needs adequate moisture to grow.

About one inch of water is sufficient for a Zinnia per week. However, you should increase the frequency if your plant lives on sandy soil.

A wonderful tip for you is using a mulch, like coconut mulch, to retain moisture longer.


Choose some liquid fertilizer types that are well-balanced and manufactured by a reliable brand. Fake products will likely deteriorate your seedling’s health and eventually lead to its death.

Avoid over-fertilizing at all costs. Excessive toxicity may not kill your plant immediately but pose a serious threat to humans if someone consumes this plant.


Thinning is a basic technique that ensures sufficient spacing between different seedlings.

If the variety in your garden is great, thin them between 6 and 12 inches apart. 9 to 18 inches are suitable spacing for small varieties.

Besides, thinning is beneficial for Zinnias’ reseeding as well. The dropped seeds cannot grow well without enough space to receive water, light, and nutrients.


When your plant reaches a height of 6 to 8 inches, pinching is needed to promote the stems’ branching and facilitate the flower’s blooming.


Deadheading comes in handy when some dying blooms pop up. If not deadheaded regularly, the blooming rate of your Zinnia is pretty low because the plant no longer pushes out new flower heads.

How To Harvest And Save Zinnia Seeds?

Below are straightforward instructions for you to consider.

Requisite Requirements

  • Look for information about the Zinnia’s harvesting and saving beforehand.
  • Prepare necessary tools, like pruning shears, paper towels, seed packets, writing utensils, etc. Don’t forget protective gloves or safety eyes. Your health is number one!
  • If you cannot undertake these two tasks, you are advised to call for a professional gardener, and he will help you out.

The Simple Procedure

  • Step 1: If you have already watered your Zinnia plants, you should wait for their flowers to dry completely before harvesting them. Harvesting too early may result in the seeds’ immature death.
  • Step 2: Cut or pull the Zinnia flowers off with the help of gardening scissors. Ensure that you keep the varieties labeled and separated.
  • Step 3: Flail the bloom’s head using your fingertips to let the seeds fall, and spread some towels on a smooth ground to gather them. Repeat this step more times if some seeds are still attached to a petal.
  • Step 4: Use your hand to spread the seeds over the towel’s surface. Let them air dry for a few days, which prevents them from molding or rotting.
  • Step 5: Store them in a small bag or paper envelope. Place them out of direct sunlight, like in the closet.

Frequently Asked Questions

How Many Types Of Zinnias?

There are several species of Zinnias, but the list as follows just includes some familiar types.

  • The Thumbelina is known for its branching flowers that can grow up to 18 inches. Its blooms also come in a range of colors, such as salmon, lavender, pumpkin, etc.
  • The State Fair is famous for its tall stems, which are between 3 and 5 inches tall. Its flowers are put into two categories, namely the semi-double and double kinds.
  • The Zahara is resistant to the invasion of mildew.
  • The Orange Star has a reputation for its light orange flowers and a bushy dwarf.

What Are The Pests And Diseases You Should Note When Planting A Zinnia?

Some species fall victim to diseases rendered by powdery mildew or fungi. Regarding the treatment, you should clip back the diseased parts of a Zinnia plant.

Then, spray some fungicide to prevent this from happening again.

When Will Zinnias Bloom?

Zinnia prefers hot climates, so early summer is the perfect time for it to flower. However, many factors affect its blooming, but the average duration is during the summer season.

Does Zinnia Come Back Every Year?


As presented above, Zinnias are annual plants that complete their life cycle, from germination to the production of seeds. So, they don’t come back every subsequent year.

The Bottom Line

Do Zinnias self seed? The answer is yes. This is a low-maintenance plant, and its reseeding nature even makes it more well-favored among gardeners.

Growing a Zinnia plant will no longer be a daunting task after you contemplate this article. It is even greater if you find tips about the caring and harvesting processes helpful.

Thank you for your genuine support, and have a nice day!

Samuel Mark

Hello I am Samuel. Samuel's Garden is a garden blog where I share my experiences in garden caring and tree growth. Hope you enjoy it!

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