How To Overwinter Mexican Petunias

Mexican Petunias, commonly referred to as Britton's Wild Petunia, Mexican Bluebell, or Texas Petunias, are often implemented as beautiful flowers in many flowerbeds that need a splash of color! If you have these flowers planted in your yard and wonder how to overwinter these plants. We've researched this question and have found substantial research results to share with you!

Overwintering Mexican Petunias is comparable to overwintering other species of flowering plants. Cut the foliage to about two inches. Next, bring the petunias indoors at the end of the growing season, right before the first frost, and place them in the basement or garage. 

Curious about how to care for Mexican Petunias throughout the seasons correctly? Or what is the lowest temperature Mexican Petunias could tolerate? We've researched these topics and have quality research results to share. Continue reading to learn more about this lovely flower. 

A small field of purple Mexican Petunias, How To Overwinter Mexican Petunias

Overwintering Mexican Petunias indoors

The term "overwintering" means bringing the plants indoors for the winter season to preserve the plants for the following growing season.

Overwintering Mexican Petunias is possible, but many gardeners choose to grow Mexican Petunias as annuals and purchase new petunias each growing season simply because Mexican Petunias are relatively inexpensive compared to the effort invested in time to overwinter the Petunias year after year. 

A blooming purple Mexican Petunia

Moreover, saving money is a wise choice in a world of high inflation. Here is how to overwinter the Mexican petunias that will save you a few extra dollars next spring! 

Steps for overwintering Mexican Petunias

  • Cut the petunias foliage to about two inches above the soil.
  • Pot the trimmed petunias in quality potting soil. 
  • Check the potted petunias for any bugs or signs of disease before bringing them indoors.
  • Bring the potted Mexican Petunia plant indoors. 
  • Please place them in the basement or the garage.
  • Only water it when the top layer of the soil is dry every three to four weeks.
  • Do not overwater. Overwatering will increase the chances of the plant dying during the winter.
  • Frequently check the plants for pests or signs of disease. 
  • Return the plant to the outdoors once the next growing season has returned.

How do you take care of Mexican petunias in the winter?

Deadheading petunias in the garden

Great question. Selecting the best method to care for your Mexican petunias over the winter is primarily based on the climate and the zone you are in.

Suppose you live in a climate where the winters are harsh. Follow the steps above for overwintering your petunias. If you live in a warm weather like Florida, you could cover the petunias with a blanket when the temperature drops to around 39 f degrees. 

Also, the Mexican petunias are considered perennial, meaning they will return the following spring after the winter months. 

Will Mexican petunias survive a hard freeze?

The Mexican petunias are native to Mexico and are commonly found growing wild throughout the southern states of the US and Mexico because the variety will thrive in hot climates. This means the Mexican petunias are not genetically capable of growing after a hard freeze.

The Mexican petunias are herbaceous perennials that, when exposed to a hard freeze, the foliage will die, and the roots remain protected in the soil. In the springtime, the petunias will grow back from the roots. 

Tips for protecting your Mexican Petunias 

Depending on where you live, you will want to either cover the flowers when the first frost arrives or uproot, pot and bring those Mexican Petunias indoors for the winter months. 

For the best results, use the link below to determine which zone you are located within and how those growing conditions pertain to your garden.

Click here to use the USDA Plant Hardiness Zone Map.

How do you cover Mexican petunias from frost?

Cutting foliage of petunias

Covering your Mexican petunias during the first weeks of the fall season is an excellent method to extend the natural beauty of your flower beds before the winter months.

Please note that there are a few different ways to protect your flowers. Select the one that is the best for your flower garden and growing zone.

If your petunias are potted, bring those inside or place a plant protector over the flowers. Suppose your Mexican petunias are planted in a flower bed. Place stakes into the ground to bolster a blanket or sheet over the plants. The stakes will prevent the plants from getting weighted down by the fabric. 

Helpful tips and tricks 

  • Provide the petunias with extra water the morning before the frost to increase humidity which will help prevent damage from cold exposure. 
  • Avoid watering the day following the frost or during particularly cold days. The moisture and water droplets on the petunias' leaves will cause damage. 
  • Add two inches of mulch around the base of the flowers to insolate the roots and improve moisture retention. 


Click here to view the Valible plant protector blanket at Amazon.


Click here to see these handy plant protectors at Amazon. 


View garden stakes at Amazon.

Do you cut back Mexican petunias in the fall?

Up close photo of gorgeous Mexican Petunias

The Farmers' Almanac recommends cutting back the petunias in the fall to encourage the flowers to return healthfully in the spring. Cutting back perennials is a great way to ensure that your flower beds will have vibrant flowers growing next spring and summer.

To do so, wait until the growing season has completed and the first frost is denoted in your local weather forecast. Then, cut the foliage about two inches above the ground with pruning shears. Use a measuring tape or yardstick to ensure you don't cut the foliage too short. 

Suppose you are concerned that roots do not have enough protection from weathering the coming cold months of winter. Place an inch or two of mulch around the base of the Mexican petunias to insolate the roots. 


Click here to view a pair of professional quality pruning shears at Amazon.

How to mulch around Mexican petunias

When using mulch, it is advised to pull weeds before mulching. Without removing the weeds before adding the mulch, those weeds will grow through the mulch and steal nutrients from the soil that the flowers could absorb instead.

Word of caution: don't use more mulch than necessary or have it uneven with areas of more than four inches in any area because over-mulching will diminish the oxygen supply to the plant's roots.

Also, over-mulching will encourage fungi mats to flourish. Those fungi mats will repel the water you want to conserve for your flowers' root systems. 

There are several beautiful varieties of Petunias you can grow in your flower beds to add more color. Click here to read "Orange Petunias Varieties You Can Plant in Your Garden."

Do Mexican petunias multiply?

Gardener repotting gorgeous petunias

Mexican Petunias multiply via spreading by rhizomes and self-seeding in gardens and wild habitats.

What is the lowest temperature Mexican petunias can tolerate?

Great question! The lowest temperature the Mexican petunias can tolerate without sustaining damage or freezing. It is roughly 39 f degrees.

Please follow the recommendations for protecting Mexican petunias from cold weather and frost mentioned earlier in this article. 

Do deer like to eat your petunias or other plants in your garden? Click here to read "Do Deer Eat Petunias? [And how to STOP them from doing that]."

In closing

A small field of purple Mexican Petunias

We at Garden Tabs appreciate you taking the time to read our article, and we hope you have found it helpful.

We discussed how to overwinter, cut back, and Mexican mulch petunias to ensure they have the best conditions to survive the winter and make a bountiful comeback when the spring season returns!

 Please check out some of our other posts before you go!

What's The Best Window For My Houseplants?

Can You Just Throw Wildflower Seeds On Grass?

31 Flowers That Need Little Water

How To Overwinter Mexican Petunias - 1600x900

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