How to Propagate Mexican Petunia? (Step-by-step) - Shiny Plant

How to Propagate Mexican Petunia? (Step-by-step)

Mexican petunias are evergreen flowering plants. Because of the high volume of flowers that they cultivate, people sometimes refer to them as flower factories. There are primarily three color options available for flowers: white, pink, and purple.

Growing these plants does not need much effort at all. Even if you put them someplace and then forget about them, they will eventually sprout and flourish. In this article, you will learn about how to propagate Mexican petunias.

So, let’s start:

Quick Guide

Common NameMexican petunia
Scientific NamePetunia spp.
Plant typeAnnual flower
Mature Size6 to 24 inches taller and 36’’ wider
Sun ExposureFull sun 
Soil Typefertile, well-drained soil
Soil pHSlightly acidic 
Bloom TimeSpring, Summer, and Fall
Flower ColorPurple, pink, yellow, white, red, orange, green
Hardiness Zones10 to 11 USDA (can be grown annually anywhere)
Native AreaSouth America

Mexican petunia

They have green leaves that are long and strip-like, and the color of the leaves is green. Flowers have a form similar to a trumpet and each has five petals. Their blooms have the same short lifespan as daylilies, much like daylilies themselves.

Early in the morning, you will be able to make out a cluster of flowers, but by the afternoon, they will have all but disappeared.

This cycle, however, repeats itself every day, which means that they bloom and fade on a regular basis. The first flowers appear in the early spring and continue to bloom all the way through winter.

Mexican Petunia

They are very hardy perennials, once planted they keep growing for years. Makes them one of the easy-growing flowering plants.

When to plant Mexican petunias

Plant them after the frost or in the fall (a few weeks before the frost). In frost, they go dormant. 

Do they grow in water?

Mexican petunias can grow easily in any kind of soil but they do not grow in water.

Can Mexican petunias be planted in pots?

Yes, you can plant Mexican petunias in pots. Read the article for more information.

Are Mexican petunias poisonous?

Mexican petunia is a wildflower, obviously, most are poisonous. But, They are completely non-toxic to humans and pets like dogs and cats.

Mexican petunia medicinal uses?

Its juice is used to make various medicine that aid in the treatment of Fever, Flu, Asthma, High blood pressure, Bronchitis, Eczema, and Diabetes.

How to Grow Mexican petunia from seeds

It is one of the best flowering plants for pots. They can be grown by division or seeds. You can choose any method, they grow very rapidly if you plant them at the right time. Plus they do not need extra care.

how to propagate mexican petunia

In fact, Mexican petunias are invasive, if not monitored they can spread all around the garden.

To grow in the pot:

  • Take a medium-sized pot around 11 inches wide. The roots like to spread deep so it is always better to have a wide and deep pot.
  • Make sure that the pot has adequate drainage holes, good drainage is a must for healthy growth.
  • Sow 2-3 seeds in the center of the pot. Do not need to sow seeds too deep, just press seeds against the soil.
  • Spray water to keep the soil moist, this plant requires more water as they bloom regularly.
  • Seeds take nearly 14 days to germinate, keep patience and let them get established.
  • Do not change the place of the pots frequently, it might disturb their growth cycle.

How to Propagate Mexican Petunia from cuttings

You can buy Mexican petunia for sale from a nursery or online. The plant must be mature or at least bloom for one year.

The division is an easy and fast method to grow multiple child plants. For division take stem cutting. You can cut any node branch, do not tear or crush the stem. It might leave permanent damage.

Clear all the buds and flowers from the stem cutting. Also, pluck all leaves from the bottom half of the plant. 

how to propagate mexican petunia

Dip the bottom end of the stem cutting in the soil and make it stand in the soil. You may dip in root hormones however this is totally optional, plants also thrive without any supplement.

Spray water to make the soil moist and leave it alone. After a couple of weeks, the stem cutting will get established. They generally self-grow and do not need to care much. Read my article on Is Mexican petunias are poisonous.

How to care for Mexican petunia plants

This flowering plant does not need special care. However, some conditions are beneficial for their growth.

Let’s see:


Mexican petunias are sun-loving plants, the more they receive sunlight the more they produce blooms. 

mexican petunia

It is important not to move their position since their petals open toward the direction from where the sunshine is coming. They are hardy enough to survive in the shady location, but the result will be fewer blooms and maybe some wilting.

The color of the flowers and the stem will change depending on the amount of light present; if the plant is grown in a more well-lit environment, it will produce more blooms that are brilliant and lustrous.

When exposed to more light, the stems take on a more purplish hue, whereas, in shaded locations, they remain entirely green.


They are drought tolerant and survive if watered occasionally in a dry climate. However, for regular bloom, you have to keep the soil moist.

Their roots are delicate, thus it is important not to add an excessive amount of water; doing so might cause their roots to deform.

When watering, always pour or spray water directly in the base, and avoid wetting the flowers and stems. Its wet parts attract fungal diseases.


Mexican petunia can grow in different types of soil, but they preferred to be planted in well-drained, fertile soil. They grow and spread quickly in marshy soil, the soil which is found near lakes and rivers.

Then it comes to pH level, they can grow in alkaline soil types but most preferably in neutral or slightly acidic soil.

Temperature and humidity

  • If you live in a cold region then you may not be able to enjoy their beauty. 
  • These flowers do not thrive in cold or low-temperature climates but can grow in summer and behave like annual plants. 
  • Grow best in dry or desert conditions but may also grow in humid climates.


Pruning encourages more bloom since new flowers grow every day. You can pluck flowers that get wilt.

Mexican petunias produce flowers in the morning which get dry till evening, this is a continuous cycle. Pluck wilted flowers, so that new buds can grow.

Ruellia simplex

They do not grow much taller, just 3-4 feet high. So you do not need any ladder to prune them.

Mexican petunias are very invasive, if you have planted them in the garden you have to monitor them occasionally, or else they can cover the whole garden.

You can control their growth by pruning, if you want to get rid of or remove small unwanted successors then just pull them out from the soil.


It is not mandatory to add fertilizer to Mexican petunia plants, generally, they are self-grown and do not need any supplements. However, you may feed them with fertilizer in the growing months. 

purple flower

You can use a garden rake to mix the fertilizer of choice into the top two inches of the soil of surrounding plants.

If you are planting Mexican petunia for the first time, you can add organic compost or manure to the soil. This will help to boost the plant’s growth and produce a lot of flowers.

When to transplant

If you have planted them in pots they may need to be repotted more frequently than other plants. As they are fast-growing shrubs. They grow well as long as planted in sunnier spots.

How to Winterize Mexican Petunia

  • Overwintering Mexican petunia is very easy, though they are perennial plants they do not produce flowers in the winter and like to go dormant.
  • If you have planted it in the pot, you can simply winterize them by Snipping off its leaves and cutting branches.
  • After Pruning, Place the pot in a dark room or where light is less. On some days they will go dormant, do not water during this dormant period. It might feel like they die, but it will come back in the next growing season.
  • Bring pot out in the early spring, when there is no threat of frost. Mexican petunia will start growing normally with regular care in a few weeks.

Did I Miss Anything?

Now I’d like to hear from you: which tip from today’s post are you going to try first?

Or maybe, I didn’t mention your favorite plant-growing tip. Either way, let me know by leaving a comment below right now.

P.S. I myself reply to every comment.

Before going if you want to grow beautiful flowers in your garden? Then click on these articles also.

5 thoughts on “How to Propagate Mexican Petunia? (Step-by-step)”

  1. Should I leave my potted Mexican petunia in the pot and transplant it in spring? Thanks for all the information in the article.

    • Hey Candy, Glad you found this article helpful.
      Yes, you can transplant it in spring. To protect from winter bring the pot inside, place it in decent light, and do not water. In early spring transplant it, with 1-2 weeks of regular watering and sunlight. It will return to normal.

  2. I live in Vegas and these plants dry out quickly so I have to water often. In the winter do I cut them all the way down? I’ve seen this done in neighbors yards but mine are in pots so don’t know if that is the same process.

    • Hey Terri,
      You can take your potted Mexican petunia inside and spread a thick layer of mulch on the soil to protect its roots from cold -protecting its root is vital. Do not water them during winter.
      Also, you can trim back them but do not cut more than 1/3 of their mass. Bring your pot outside once winter gets over. After regular watering, it will regrow.
      Also, if your plant dries quickly, spread a thick layer of mulch around the plant, it will help to retain moisture for a longer duration.
      Thanks, for visiting. Happy gardening.

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