How to Fix Brown Spots in Grass So They Don't Come Back

How to Fix Brown Spots in Grass So They Don't Come Back

Treating Lawn Fungus and Other Grass Issues

Nothing interrupts the beauty of a lawn like brown spots in grass. Besides being an eyesore, they can lower your curb appeal and threaten your entire lawn. Keep reading to find out how to get rid of these brown spots, especially if they are caused by a nasty lawn fungus.

Why is my grass brown


Why is My Grass Brown?

Brown spots in grass have various causes. Some of the most common include:

  • Dormant Grass: Grass, especially in northern climates, will go dormant during long droughts. This state of dormancy is a survival mechanism and will turn the grass a brownish color. After a good watering, either from rain or a sprinkler system, the dormant grass will turn green again.

  • Pet Spots: Dog urine spots, or pet spots, are caused by Fido using the bathroom in one concentrated spot on your lawn. The chemicals in the urine can damage or kill the grass. If you can't train your pet to go elsewhere, rinse the area with water when it has finished doing its business.

  • Thatch: There's a layer between your grass and soil composed of organic matter like dead grass, leaves, etc. This is called thatch and, while a little bit is beneficial, too much of it can starve your soil of water and oxygen.

  • Lawn Fungus: There are many different lawn fungus types that attack and kill your grass. Like other types of fungus, they thrive in cool, moist, shaded environments. We'll talk more about them below.

  • Dead Grass: If dormant grass goes too long without water or lawn fungus is left untreated, the grass will eventually die. You can tell whether grass is dead or dormant by pulling on it. If it comes out easily, it is dead.

Out of those common causes of brown spots in grass, lawn fungus is the most sinister (aside from the dead grass of course). That's why we'll cover how to prevent and treat lawn diseases below.

white lawn fungus

What Causes Lawn Fungus?

In most cases, a fungus is harmless. Sometimes, though, as brown and yellow spots become visible, it will become evident that your lawn has contracted fungal disease, putting a blight on your yard. The causes of lawn fungal disease include:

  • Lack of water
  • Mowing with too low of a setting
  • Overwatering or watering at night
  • Too much fertilizer
  • Erratic variances in temperature and humidity

Lawn disease is most likely to occur after several days of humid weather, especially if there's little sun. Any time the grass gets too moist without the chance to dry, the risk of fungus increases.


How to Treat Lawn Fungus Naturally

The best method of treating lawn fungus is prevention. So, before you pull out the chemicals, try these natural lawn fungus control steps: 


Fertilize Your Lawn Appropriately

Using too much fertilizer can make your grass prone to fungi. Too little fertilizer can do the same. If you are concerned about fungus on your lawn, it may be a good idea to try an organic, slow-release fertilizer.


Fertilizing soil


Excess nitrogen in synthetic fertilizer quickly makes a lawn green but can also disturb the natural ecosystem of the lawn. If you want your grass to be less prone to disease, organic fertilizer may be the right solution.


Only Use as Much Water as Necessary

Try watering less frequently for a longer period of time. It's also best to water your grass in the morning so the water has a full day to absorb into the soil or evaporate.


NEVER water at night because the grass will stay wet in the dark and make a perfect home for fungi.


Dethatch Your Lawn

As mentioned above, thatch is a layer of dead grass or roots that covers up your lawn, slowly starving it of air. Once you remove the layer of thatch from your lawn, your soil will have the opportunity to breathe and won't be as vulnerable to fungal outbreak. 


Aerate Your Soil

Aerating, or poking holes in the ground, loosens your soil to help create a good growing environment. It also creates better drainage for water, so it doesn't become stagnant and attract fungus. Read our aerating guide for more information.


aerating soil


Mow Your Lawn at a Higher Setting

Mowing too low can encourage fungal disease by leaving your grass defenseless. Keep your grass at a height of 3 to 4 inches, and never cut more than one-third off during a lawn mowing session.


Sharpen Mower Blades

Dull mower blades shred the grass instead of cutting it, which makes it more prone to fungal spores. For a clean cut,you should either sharpen or replace your lawn mower blades after every 25 hours of use.


Evaluate Your Grass Type

Ensure that your grass type matches the climate you live in. Certain ornamental or exotic grasses may not be suitable for your soil or climate and will e more susceptible to lawn disease. If your grass is a bad fit, you may want to consider re-seeding.


Fungicide Lawn Fungus Treatment

As a last resort, you may want to try a fungicide on your lawn. A fungicide can eradicate your lawn disease as you work on improving your lawn care regimen to prevent fungi from coming back.

Spraying fungicide

There are two main types of fungicide. Liquid fungicide creates a liquid coat over the grass that kills the fungus spores. Granule fungicide comes in little pellets that are spread on the grass and get absorbed into the soil. Remember, fungicide is a chemical, so always wear proper personal safety equipment when using it, like gloves, goggles, long clothing and safety masks.


Take Care of Your Lawn

Like with anything else, if you neglect your lawn, you'll run into problems. Always mow your lawn correctly, and ensure it receives enough water, air, and sunlight. Those best practices should keep brown spots off your lawn for good.

NEXT: How to Rescue Your Lawn


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