Brown patches of grass on the lawn are a very common occurrence. It’s understandable to feel frustrated and dismayed when you see brown spots on your lawn. Especially if you have been working hard to keep it looking healthy and lush. Today I’ll answer the common question “Why is my lawn turning brown in spots?” provide a list of the most common causes, and share simple solutions to get your lawn to green up again in a hurry.
Common Reasons Why Lawns Develop Brown Spots
Brown grass usually indicates that, in one way or another, the grass is not getting the water or nutrients that it needs to thrive.
Here is a list of the most common reason for brown patches in your lawn:
- Weed Pressure
- Chemical Burns
- Pests & Disease
- Forgotten Toys and Tools
Below I’ll go over each common reason why your lawn is turning brown in spots, and share my best advice to address the underlying issues that have caused your ugly, brown-spotted lawn.
Drought: A Common Cause of Brown Spots
It is customary for grass to turn brown when there is not enough moisture in the soil. If your lawn is turning brown in spots after a long stretch with high heat and little rain (and you don’t have an irrigation system), drought is probably the cause.
Has your grass died?
Probably not. Usually grass that doesn’t get enough water simply goes dormant to protect itself, and will green up again when watered regularly.
If this is your situation your grass will come right back to its lush green color after it has had a good watering.
You can always wait for temperatures to cool and rain to arrive, but if the brown spots in your lawn are bothering you, get an oscillating sprinkler water your lawn. Most turf-grass does best with about an inch of water per week.
Also, when watering your lawn, make sure that your sprinkler is reaching all the spots on your lawn. This may be another reason why you have dormant grass in hot weather.
You might believe you are being diligent in watering your grass, but have actually been missing spots that then become dormant.
This might be why you notice that your lawn is turning brown in spots due to drought.
When you water your lawn, try to do so early in the day so that your grass has a chance to absorb the water before the heat evaporates it.
Weeds Can Cause Brown Spots in Your Lawn
Weeds and grass compete with one another for the same nutrients, the same sunshine, and the same water.
If there are too many weeds in your lawn, then they can ultimately win out over your grass and kill it.
Your lawn can also experience patches of dead grass or bare patches if there has been weed dieback, particularly of annual weeds that die at the end of the season. As patches of weeds die, they can lead to your lawn turning brown in spots in the fall, revealing areas of your lawn which were primarily annual weeds and not turfgrass.
You can manage bare spots from weed dieback pretty easily. Just spread some grass seed. A patch and repair variety is particularly effective in these scenarios. They tend to grow quickly and have an all-in-one mixture.
Try to choose a product that has perennial grass seed, not annual grass seed or you’ll be fighting the same issue next year. You can read my guide to fixing a patchy lawn to learn more.
There are a number of ways to deal with weeds depending on what season you’re in.
Chemical Burns from Fertilizer
Another very common reason your lawn is turning brown in spots is overusing or spilling fertilizer or spilling other chemicals on your lawn.
This results in either a chemical burn or a change in pH in your soil, which will cause your grass in that location to die.
To avoid these types of chemical burns, it is important to use fertilizer as directed and to dispose of other chemicals properly.
Avoid pouring gasoline into your lawnmower on your lawn and instead, do it in the garage or on your driveway.
Too much nitrogen can specifically cause these kinds of burns, whether the nitrogen comes from spilling fertilizer as you turn your broadcast spreader or from animal urine.
That’s right, dogs or other animals peeing on your lawn also kills grass due to the high nitrogen content in their urine.
Encourage your dog to pee elsewhere in your yard or take them on a walk to avoid urine burns on your lawn.
Pests and Disease
Fungus and grubs and bugs, oh my!
There are a few bug culprits in particular that cause brown spots on the lawn. Grubs are arguably one of the most common pests in a lawn. Grubs are the larvae of June bugs. They hatch underground. As the larvae develop, they eat the roots of your grass, which ultimately leaves you with brown patches as the grass dies from being unable to get any nutrients.
I have a guide for ways to get rid of lawn grubs that you may interested in reading.
Skunks also love to dig up patches of lawn to scavenge grubs and that creates a whole other level of lawn damage.
Grubs can be easily treated with certain types of nematodes or milky spore powder available online or at your local garden center (this product is my go-to). They can also be prevented entirely by ensuring that your lawn completely dries out between waterings.
Similar to grubs, cinch bugs drain your plants dry. They thrive in drought conditions so it is easy enough to prevent an infestation by ensuring adequate moisture. Avoid using insecticides as these can often do more harm than good.
Finally, mold and other fungi can damage your lawn.
This often occurs when there is too much moisture. Identifying factors include the plentiful growth of mushrooms in your lawn or grass that is covered with white or black mold.
Avoid watering too late at night as the moisture can linger for too long and create an ideal environment for fungi to thrive. A lawn that is overrun might need a landscaping expert to help solve the problem or kill off the entire lawn and start from scratch.
Forgotten Toys or Tools
Leaving items on your lawn even just for a day or two, but especially for longer periods of time, can create brown spots.
The item on the grass prevents that patch of grass from getting the sunlight, air, and water that it needs to thrive. This can cause a patch of grass to go dormant, such as in a drought situation.
However, if an item is left on the lawn for too long, such as a playset, then the grass underneath will ultimately die.
You can prevent this by picking up toys and tools off of the lawn at the end of each day.
Brown spots from temporary items will recover quickly on their own but spots that were covered for longer periods of time might benefit from using a patch and repair mixture like this one from Scott’s on Amazon.