Having brown, dead patches of grass in your lawn can be unsightly and frustrating. Understanding the potential causes of these dead spots is the first step to restoring your lawn to its former green glory.
Common causes of dead patches in lawns
There are several common culprits that can lead to dead or thinning areas in your lawn:
Lack of water
Insufficient watering is a very common cause of browning areas in lawns. Grass needs about 1-1.5 inches of water per week from rain or irrigation during the growing season. Going too long between waterings causes the grass to dry out and die. Drought conditions make this worse.
Compacted soil
When soil becomes overly compacted, air and water have difficulty penetrating down to the grass roots. This can lead to root decline and dieback. Heavy foot traffic, excessive thatch buildup, and heavy equipment rolling over the lawn are common causes of soil compaction.
Disease
Lawn fungal diseases like brown patch, dollar spot, and gray leaf spot can create dead patches ranging in size from several inches to several feet. Excessive moisture favors disease development. Fungal diseases may cause turfgrass blades to wither and turn brown or gray.
Insect damage
Underground lawn pests such as grubs, billbugs, or armyworms feed on grass roots and stems, which causes dieback. Aboveground insects like sod webworms and cutworms chew on grass blades. All can leave behind irregular dead patches.
Shade
Overly shady areas prevent grass from getting enough sunlight to thrive. Tree leaves also restrict airflow and retain moisture, encouraging fungal issues. Grass under large trees or shrubs often struggles.
Herbicide damage
Misapplication of a lawn herbicide can create dead patches. Using the wrong type of herbicide, applying too high of a dose, or spraying in hot weather when grass is stressed increases chances of damage.
Pet urine
The high nitrogen and salts in dog and cat urine can burn grass blades, leaving yellow or brown patches. These dead spots often have defined edges.
Poor drainage
Standing water or chronically wet, swampy areas suffocate grass roots, eventually killing the turf. Low spots and compacted soils that limit infiltration are prone to poor drainage.
Less common causes of dead lawn patches
While less likely, a few other issues can also create dead or thinning turf:
Nutrient deficiencies
Lack of essential nutrients like nitrogen, potassium, and phosphorus can starve grass plants. This causes gradual thinning. Deficiencies are uncommon in well-maintained lawns but may happen in very sandy or acidic soils.
Salt damage
Heavy application of deicer salts on driveways and sidewalks during winter can leach into soil bordering paved areas. High salt accumulations damage grass.
Buried debris
Buried construction debris or large rocks prevent proper root development. Grass above these obstructions may thin and die.
Heavy thatch
A thick layer of undecomposed organic matter called thatch can prevent water, nutrients, and air from reaching the soil and roots. Excess thatch buildup causes turf decline.
Compaction
Excessive foot traffic, equipment use, or soil compaction creates dense, hard soil that restricts root growth and causes dieback.
Mowing issues
Scalping lawns by mowing too short or uneven mowing patterns causes stress that can thin and weaken turf over time.
Air pollution
Nearby industrial operations or heavily traveled roads can expose grass to pollutants that restrict growth. This causes gradual thinning.
Rodent damage
Tunneling and feeding by gophers, voles, or other burrowing rodents kills grass. Mounds of loose dirt are evidence of their activity.
Diagnosing the cause of dead lawn patches
It takes careful observation and detective work to determine exactly what’s causing dead grass patches. Consider the following:
- Pattern of damage – Random spots often indicate disease, insects or urine burns. Large irregular patches point to drainage issues, shade, or compaction.
- Edge of dead patch – Defined edges suggest disease, insects, or urine. Gradual thinning indicates lack of water, nutrients, or compaction.
- Color – Yellowishdead grass points to dog urine, heat/drought stress, or nitrogen deficiency. Gray or black means disease. general browning indicates other issues.
- Timing – Summer damage implicates drought, disease, or urine scorch. Fall or spring damage implicates pests, disease, or compaction.
- Locations – Patches near downspouts or low areas indicate drainage problems. Damage under or near trees signals shade issues.
- Distribution of damage – Random scattered spots suggest disease or insects. Large irregular patches point to other issues.
Additionally, a close physical inspection of the lawn and roots can reveal issues. Sending samples to a lab for analysis can definitively diagnose diseases, insect damage, or nutrient problems.
Preventing dead spots in lawns
Prevention is the best medicine when it comes to avoiding dead patches in your lawn. Here are some key tips:
- Mow high – Longer grass blades promote deeper roots. Avoid cutting below 3 inches.
- Fertilize appropriately – This builds root reserves and strengthens turf against stress.
- Water deeply – Wet soil 6-8 inches down to encourage robust roots.
- Improve drainage – Regrade or add amendments to dry out chronically wet areas.
- Reduce thatch – Detatching and aerating helps decompose excess thatch.
- Control pests – Treat for damaging insects, diseases, and weeds to protect turf.
- Overseed thin areas – Quickly fills in dead patches to prevent weeds from invading.
- Limit traffic – Rotate activities to different lawn areas to prevent excessive compaction.
Additionally, selecting disease and drought resistant grass varieties suitable for your climate helps minimize problems down the road.
Fixing dead grass patches
Once you’ve diagnosed and addressed the underlying cause, focus on repairing dead areas. Here are some options:
Spot seeding or overseeding
Sprinkling grass seed over dead patches allows surrounding healthy grass to fill in bare spots. Overseeding larger thin areas also works. Just be sure to maintain consistent moisture for seed germination.
Sodding
Laying sod is the quickest route to filling in substantial dead patches. Cut out dead grass, level the soil, and lay new sod over trouble spots for an instant fix.
Plugging or sprigging
Plugging involves transplanting small chunks of living grass into dead areas. Sprigging uses grass stolons or rhizomes inserted into the soil. Both allow regrowth from living grass tissue.
Topdressing
Adding a thin layer of quality soil or compost over damaged areas helps rejuvenate the lawn. Be sure to feather out edges for a seamless look.
Aerating
Punching holes in compacted soil provides channels for improved airflow, drainage, and root growth. Core aeration helps remedy compaction issues.
Adjusting irrigation
Increasing watering frequency or run times supplies needed moisture if drought stress caused dead grass. Or, improve drainage to eliminate standing water in swampy spots.
Reseeding
For large dead patches or completely bare areas, strip out all existing grass and debris. Work the underlying soil until smooth and blended. Reseed the area for a fresh start.
| Cause of Dead Patch | Repair Method |
|---|---|
| Disease | Spot treat with fungicide, plug, sod, or reseed |
| Insect damage | Treat for pests, overseed, sod, or plug |
| Compaction | Aerate and topdress or overseed |
| Poor drainage | Improve drainage, plug, sod, or reseed |
| Drought | Adjust irrigation, overseed or sod |
| Urine scorch | Flush soil, overseed, sod, or plug |
| Shade | Prune trees, reseed with shade grass |
With patience and diligent troubleshooting, you can get your grass growing green again in those unsightly dead patches. Just be sure to address the underlying cause or the problem will likely return.
Conclusion
Dead patches in an otherwise healthy lawn are frustrating, but they’re rarely a lost cause. A little detective work to determine the trigger, followed by appropriate corrective steps, can restore your turfgrass to its former glory. Focus on improving overall lawn health through proper mowing, fertilization, irrigation, and pest control to prevent factors that contribute to dieback. With timely intervention and sound cultural practices, you can green up those ugly brown spots.