An overwatered St Augustine grass is characterized by curling leaves that may also turn yellow.

Overwatered St Augustine Grass

While in this state, the Augustine lawn is highly susceptible to root rot and attacks by a fungus that is referred to as the “brown patch.” All these properties around an overwatered St Augustine lawn steal the attractive vibe of the plant.

To learn how you can protect your plant from overwatering or save it if it has already been affected, continue reading this comprehensive guide.

Why Does My St Augustine Grass Appear Overwatered?

Your St Augustine grass appears overwatered because of using the same watering schedules in winter and summer, adding too much water when irrigating, growing the plant in compacted soils, not considering temperature changes, using liquid fertilizers without proper planning, and failing to control pests and diseases.

– Temperature Changes

The rate at which your grass and its soil release water are highly controlled by temperature conditions.

When temperatures rise, more evaporation and transpiration take place, both of which reduce the amount of water that remains in the soil. This reduces the probability of having your St Augustine grass overwatered. Lower temperatures are linked with reduced rates of water loss.

Adopting a habit of watering your lawn at night could also cause overwatering problems. At night, temperatures are far lower and evaporation is less likely to happen, especially in winter. In warmer seasons, very little evaporation can take place.

During the night, the pores that release water via transpiration are closed and so water cannot be lost to the atmosphere. All these factors point to one thing 一 increased accumulation of water in the soil, thereby supporting waterlogged conditions.

– Using Compacted Soils

The St Augustine lawn will thrive well on any soil type, as long as they are not compacted. The grass grows best when the soil on which it grows allows free movement of water so that the roots won’t sit in a highly aqueous environment.

When soils are compacted, there are few to no breathing spaces available. Therefore, air cannot circulate well to support the needs of your lawn.

This is a characteristic of poor soil quality. Such an incompetent soil quality also even worsens when the grass is watered because then the few air spaces available are clogged with water particles, making it even more difficult for the roots of your lawn to breathe.

Poor soils suppress access to important resources for growth by the St Augustine grass. As a result, the grass blades may turn brown or yellow. This marks the beginning of the destruction of your once-beautiful lawn.

– Adding Too Much Water

The St Augustine grass can stay for up to five days before getting its next drink. Of course, this may also be affected by the available temperatures at a given time.

However, it is important to note that too frequent watering schedules cause excess water to accumulate in the soil, a scenario that is characteristic of waterlogged conditions.

Sometimes, overwatering results from watering for too long in one session. Ideally, we recommend that you should run your sprinkler for approximately 30 to 40 minutes if it’s a pop-up one.

dealing with an Overwatered St Augustine Grass

If you are using a rotating sprinkler, watering for a minimum of an hour and a maximum of half an hour is commendable. Any watering time frames that exceed the ones that we have stipulated are more likely to expose your lawn to a state of overwatering.

– Using the Same Schedules in Summer and Winter

If you notice your St Augustine grass turn yellow or have brown spots, you might need to check if your watering schedules match the seasons in which you are. In winter, the lawn enters a period of dormancy, so it is unlikely going to use much of the water that you give it, which is why you should limit watering.

If you water the same way you would in summer, your Augustine grass will certainly sit in water. However, always remember to factor in environmental conditions, considering that some winter days are relatively warmer and windy, so water loss may be a little higher.

In summer, your lawn will be experiencing a period of active growth. As a result, it uses up more water so the soil gets dry at a relatively faster rate compared to what would happen in winter. Moreover, temperatures are usually higher in summer, which further aids the evaporation and transpiration rates.

– Unplanned Use of Liquid Fertilizers

Depending on the dilution factor, adding liquid fertilizers may have similar effects to a session of light watering. This means that if the fertilizer is added more frequently than the six to eight week period that we recommend, you might have to deal with overwatering.

Another way in which adding liquid fertilizer may contribute to overwatering is when you fail to strategically plan the sessions well.

For example, if you don’t combine the watering and fertilizing sessions, the latter may appear as a standalone drinking event for the lawn. This way, it may appear as if the St Augustine grass has been watered more frequently than it should.

Take note that we are not discouraging the use of fertilizers on your lawn, considering that this supplementation makes the St Augustine grass grow. Adding fertilizers helps to curb cases of potassium, phosphorus, and nitrogen deficiencies.

– Failure To Control Pests and Diseases

Failure to carry out basic and proper lawn care could be the reason behind the overwatered state of your St Augustine grass.

These include simple pest and weed control, as well as addressing lawn diseases like the brown patch disease. Weeds tend to make the soil around your St Augustine lawn more compacted, thereby promoting poor drainage and waterlogged conditions.

Diseases that affect the St Augustine grass compromise the lawn’s efficiency in taking up water and using it. Such a scenario keeps the soil wet for extended periods of time. If you assume that your grass is well and follow your normal watering schedules, overwatering may result.


How Do I Revive an Overwatered St Augustine Grass?

To revive an overwatered St Augustine grass, you can try to enhance the lawn’s drainage system, follow reasonable watering schedules, control pests and diseases, and address root rot. We will give some effective and tried and tested nuggets in this section.

Whether you are dealing with a case where the St Augustine grass turns yellow, the roots are attacked by root rot, or the lawn is dead, there are strategies that you can employ.

– Enhance Drainage System

While the St Augustine grass grows relatively well in any soil environment, clay soils are not a good option to consider. The texture of this type of soil is too fine, while the structure is highly compacted.

These characteristics will leave your lawn with no option but to sit in water. Therefore, avoid using clay soils and grow your St Augustine grass on mediums that have better water-draining capacities.

Save My Overwatered St Augustine Grass

At times, soils become increasingly compacted as time progresses due to watering and other factors.

This is irrespective of whether you initially used well-draining soils or not. If this is the scenario that you are facing, you can use a hand garden fork to loosen up the soil. Be sure to do this as gently as possible so that you don’t damage the roots of your lawn.

– Follow Reasonable Watering Schedules

As we mentioned earlier, watering schedules are dependent on many factors, including environmental and seasonal changes. However, there are general watering guidelines that can inform the timing of your watering sessions.

If your lawn is still healthy, we recommend that you water it about three times every week. When it’s summer, your lawn may endure one to five days without getting another drink. Avoid stretching for too long without watering your plant as this makes it vulnerable to drought stress.

You can consider checking the moisture of your lawn’s soil before you water it again. Make sure it is not soggy or wet before you water. You can dip a stick into the soil and see if it comes out with wet soil. Alternatively, you can use a moisture meter, which is a more effective strategy.

– Control Pests and Diseases

Depending on how much your lawn has been affected by the patch disease, you might need to employ some interventions. First, you can remove the affected parts of your lawn so that this lawn fungus doesn’t spread to healthier areas. This has to be done earlier because the brown patches can rapidly spread.

We also recommend that you apply fungicides such as flutolanil, thiophanate-methyl, azoxystrobin, or Consan 20.

Another way to revive St Augustine grass blades is by destroying grub worms. These pests damage the roots of your lawn so once they have been dealt with, the roots will have access to the resources that make the grass green again. Trichlorfon and carbaryl are effective in controlling grub worms.

– Address Root Rot

When parenting the St Augustine grass, root rot is better prevented because there are no fungicide products that can cure this infection. The best that you can do is to slow down its spread. We recommend watering deeply but less frequently rather than engaging in shallow but frequent drinking sessions.

Remember, root rot can completely kill your lawn. Once all the roots are damaged, the grass blades will lack a sufficient supply of resources such as water and nutrients. This will lead to the death of the St Augustine grass.

Take note that there is no way to revive dead lawns. When the overwatering situation ends up leaving you with dead St Augustine grass, the only option is to grow a new lawn to have a new, healthier version.

Frequently Asked Questions

– Can My St Augustine Grass Recover From the Brown Patch Disease?

Yes, your St Augustine grass can recover from the brown patch disease and assume its beautiful color again, but it will only be done by regrowing the unaffected parts of your lawn. However, you might have to wait until summer, which is the season when the lawn actively grows.

Take note that applying a fungicide will not make the affected grass regrow but will prevent the fungus’ spread to unaffected parts. Recovery will only take place by regrowing the affected regions of the lawn.

– How Do I Diagnose Root Rot on My St Augustine Grass?

To diagnose root rot on your St Augustine grass, you will notice that the lawn roots appear brown or black. In addition, the roots will release a bad smell because they are already rotten. The healthy roots are normally whitish and don’t have a foul odor.

Save Overwatered St Augustine Grass

– Is Hydrogen Peroxide Effective Against Root Rot?

Yes, hydrogen peroxide is effective against the fungus that causes root rot. However, the challenge with St Augustine grass is that uprooting it and treating it with hydrogen peroxide is cumbersome and time-consuming. On a relatively large scale, carrying out the treatment might be impossible.


The St Augustine grass can beautify your spaces, but not when it is overwatered. This guide has enlightened you on how you can prevent getting your lawn overwatered and how you can rectify the problem where possible, so here are some of your take-home nuggets:

  • An overwatered St Augustine grass may turn yellow or brown or may even have brown patch disease or root rot in the worst-case scenario.
  • Some of the main causes of overwatering on this lawn are using compacted soils, failure to consider temperature changes, and adding too much water.
  • The best way to avoid an overwatered scenario for your St Augustine grass is by ensuring that it grows on a well-draining medium.
  • Take note that dead St Augustine grass cannot be revived. 

You have just earned yourself the expert knowledge to deal with cases of overwatering on your St Augustine grass. Enjoy the journey of applying your knowledge!

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