Will Petunias Come Back if Under-Watered?

It’s very easy to underwater your petunias. Since they don’t need a lot of water it can be quite easy to forget to water them from time to time. If your petunias have begun to show signs of underwatering, you might wonder if they’ll ever come back to the beautiful, sunny plants they used to be.

Petunia’s will come back if underwatered provided that they aren’t too far gone and you adhere to a proper watering schedule. Generally, once a week watering for your petunias should be enough to restore them. 

In the rest of this article, I’ll explain the best ways to support your petunias’ growth if they’ve been underwatered. I’ll also help you identify underwatered petunias and explain why underwatering is so bad.

How Do You Fix Petunias That Have Been Underwatered? 

The good news is that petunias are fairly easy to revive once they’ve been underwatered. If you catch them early enough, you may even be able to save some of your plants before they’ve been damaged beyond repair.

To fix under-watered petunias, monitor the moisture in the dirt and water carefully. Use a mister setting if possible, or put the water directly into the soil. 

You should probably consider using proper irrigation or a sprinkler system in the future to ensure your petunias are getting all of the water that they need. 

Checking on your petunias consistently is key to ensuring they return to life. You can also do a few extra things to save time and money. 

Check Your Soil Texture for Compaction

Checking your soil for moisture will indicate whether your petunias have been underwatered. One major indicator here is soil compaction.

If you’re already watering your plants properly, and the plants are still underwatered with bone dry or compacted soil, then the soil might be the problem.

Check your soil for moisture by digging up a small handful of dirt and squeezing it in your hand. If the soil crumbles easily and feels fairly loose, it’s healthy. However, if the dirt is extremely dry or hard as a rock, you will need to focus on your compaction issues rather than watering. 

I’d suggest taking out the petunias and putting them in fresh, easily draining soil and dealing with the compaction issues separately. In this article, I explain how to fix your compacted soil: 7 Reasons Why Your Soil is So Compacted (DIY Fixes)

Re-Hydrate Underwatered Petunias With Bottom Watering

If your petunia has been underwatered for a while, immediate rehydration might be more important in the short term than an increased watering schedule.

Bottom watering is already a great watering method but it’s especially good when your plants are underwatered. Here’s how to rehydrate underwatered petunias with bottom watering.

  • Place the planter into a tray of water. Note that your planter must have holes at its base for this to work.
  • Leave the planter until the moisture reaches the top of the soil. Ideally this should take 30 minutes to an hour but can vary depending on your soil/potting mix. If you’re unsure how long to leave it for, stick your index finger into the potting mix. Once you can feel moisture around an inch beneath the topsoil, take it out of the tray.
  • Drain the planter. You can do this in another empty tray or simply take it outside. Once it’s stopped dripping, you can return it to its usual position.
  • Keep the plant leaves moist with a spray bottle.
How Bottom Watering Works

This video shows gives you a nice visual how you can do this with large petunias:

To learn more on watering plants from the bottom, you could check out my other article: How to Water Plants from the Bottom (Beginner’s Guide)

Use a Moisture Meter To Keep Track of Petunia Soil Moisture

A moisture meter measures the amount of water in the soil by sending an electrical current through it. ‘This can help you determine whether you should add more water or not so that the plants don’t get too wet or too dry at any given time of day or season of the year. 

Many meters give you specific readings but for beginners you can opt for a simpler option like this Soil Moisture Meter on Amazon. It has the conventional readings but also comes with a simplified design to better understand the different moisture levels.

If your moisture meter indicates that your petunias are dry, water them! They may be sucking up water faster than you’re used to if it’s hot out or the pot is draining too fast. Always keep the soil moist when dealing with petunias, especially when trying to nurse them back to health post-under-watering.

How To Spot Underwatered Petunias

Spotting your underwatered petunias is almost as important as fixing the problem. Since you can’t fix a problem you can’t identify, it’s vital to know how to spot underwatered petunias.

The most common sign of underwatered petunias is wilting. Wilting leaves mean that there isn’t enough water being taken up by the roots to support healthy growth. 

Overall there are three common signs of underwatering. Keep a lookout for:

  • Wilting Petunias: Like any other plant, they will begin to wilt if they receive too little or too much water.
  • Leggy or Stunted Petunias: Underwatering petunias can cause flowers to be stunted and leggy with weak stems. 
  • Non-flowering petunias: When you underwater your petunias, you can expect them to flower less frequently. In fact, they may not flower at all. This happens because the plant needs enough water to produce flowers and fruit.

How Watering Affects Petunias

Water is vital to plants — petunias being no exception — but as bad as not getting enough can be, getting too much water can sometimes be even worse. As a result, it’s important to know just how important moisture is to your plants.

Underwatered Petunias Will Wilt and Die

Underwatering can damage your plants and petunias, in particular, don’t do well in dryness. If the soil around the petunia plants becomes too dry, the roots won’t be able to absorb water from the soil down below and will begin to die off. 

This will result in wilting leaves and stunted growth of your petunias. If left untreated long enough, this condition can lead to the death of your plants.

Watch Out for Over-Watering, Too!

When you’re overwatering your petunias, you might notice that they start growing much faster than they did previously and produce more flowers than usual.  

However, they may also become leggy because they haven’t been given proper time to grow. This results in long plants with weak stems.

Excessive water can also cause soil compaction  

Ideal Watering Conditions for Petunias 

Ideally, you should water your petunias at least once a week. Petunias are not particularly thirsty plants, so a weekly watering schedule can work just fine. Of course, you can bump it up to twice-weekly intervals if you feel your plant needs more water. 

While once a week is a good base, it’s also vital to remember that differences in seasons, temperatures, and humidity can all account for differing water loss in petunias. As a result, what works for other people might not work for you. For some zones, watering once a week is fine but it might be different for a different zone.

Regardless, a foolproof method is to always manually check the moisture in the soil and adjust your watering accordingly.

A watering can with a small nozzle would be a great option here for a light spray. However, you can also bottom water your plants from time to time to completely hydrate your soil. 

If you have an automatic waterer, ensure that it is set to only give your petunias enough water for their needs and nothing more than that. 


Underwatering your petunias is not always a death sentence for the plants. With proper care and hydration, your petunias should eventually recover. 

That said, it’s also important to first, note that your problem is actually underwatering. Overwatering and underwatering can appear similar and treating one in place of the other can be disastrous for your plants. 

To avoid this, you should always manually check the moisture in the soil around your plants either with a simple finger test or a moisture meter.

Alexander Picot

Alexander Picot is the principal creator of TheGrowingLeaf.com, a website dedicated to gardening tips. Inspired by his mother’s love of gardening, Alex has a passion for taking care of plants and turning backyards into feel-good places and loves to share his experience with the rest of the world.

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