Your lawn was fine last week. Looked good, actually. Now you’ve got yellow patches spreading across different sections and you’re wondering what the hell happened.
Yellow spots don’t just show up for no reason. Something’s stressing your grass. Could be disease, bugs, water problems, missing nutrients – honestly the list is longer than you’d think. The frustrating part is figuring out which problem you’re actually dealing with so you can fix it instead of just throwing solutions at the wall hoping something sticks.
We’re going to cover the common causes of yellow spots around North Georgia and how to tell what’s going on with your specific lawn. Once you know the cause, fixing it is usually pretty straightforward.
Fungus Is Usually the Culprit
If those yellow or brown spots appeared suddenly when it was hot and humid out, you’re probably looking at fungal disease. Our summers here – hot days, humid nights – create ideal conditions for lawn fungus to take off.
Brown Patch
Brown patch shows up as circular yellow or brown areas. The grass blades look water-soaked and dark when infection starts, then they turn tan or yellow as they die off. Often you’ll see a darker ring around the edge – that’s where the fungus is actively spreading.
This disease thrives in heat and humidity. Most outbreaks happen June through September when nighttime temps stay above 70 degrees and humidity is high. Bermuda and Zoysia get it, but tall fescue lawns really suffer from brown patch.
It’s caused by too much moisture sitting on grass blades overnight combined with warm temperatures. If you’re overwatering, have poor drainage, or watering in the evening, you’re setting yourself up for brown patch.
How to treat it: Fungicide stops the spread. But more important is adjusting your watering – early morning only. Improve drainage in problem spots. Skip the high nitrogen fertilizer during summer when disease pressure is high.
Dollar Spot
Dollar spot creates these small circular yellow or straw-colored patches roughly the size of a silver dollar. Multiple spots usually merge together into bigger irregular areas. If you look at individual grass blades, you’ll see tan lesions with reddish-brown borders.
Unlike brown patch, dollar spot shows up when lawns are stressed from low nitrogen or drought. Most common in spring and fall when temperatures are moderate but you haven’t been feeding the lawn enough.
Treatment: Apply nitrogen fertilizer to the stressed areas. Sometimes that alone stops dollar spot from progressing. Severe cases need fungicide too. Water deep but not frequently – reduces leaf wetness that encourages fungus.
Rust
Rust makes grass look yellow-orange. Like it’s literally rusting. Rub your hand across the grass and you’ll get orange powder on your skin – fungal spores.
Shows up most in late summer and fall on lawns that aren’t getting mowed regularly or growing slowly because of drought stress or low nitrogen. More common on tall fescue and ryegrass than Bermuda or Zoysia around here.
Treatment: Fertilize to get growth going. Mow regularly to remove those infected leaf tips. Rust rarely actually kills grass, it just looks terrible. Once the grass starts growing vigorously again, rust goes away on its own.
Bugs Create Irregular Yellow Patches
Sometimes those yellow spots have nothing to dWhen You Should Call a Proo with disease. You’ve got insects feeding on grass roots or sucking nutrients from the blades.
Grubs
White grubs are beetle larvae. They feed on grass roots late summer through fall. Affected areas turn yellow first, then brown. The turf feels spongy when you walk on it. Grab the grass and it lifts right up like carpet because the roots have been eaten away.
Most damage shows up August through October in North Georgia. If you’ve got more than 5-10 grubs per square foot, that’s above treatment threshold and you need to deal with it.
Pull back a section of that affected turf and look in the soil. Grubs are C-shaped, white to cream colored, about an inch long. If you find them, mystery solved.
Treatment: Grub control insecticide applied late summer kills larvae before they do extensive damage. If damage is already visible in fall, treatment won’t help this season – you’re treating to prevent next year’s generation. Reseed the damaged areas in fall.
Chinch Bugs
Chinch bugs suck plant juices from grass blades. Causes irregular yellow patches that gradually expand and turn brown. Damage looks a lot like drought stress. Often appears near driveways, sidewalks, other hot areas.
Most active during hot, dry weather. St. Augustine is highly susceptible but chinch bugs also go after Bermuda and Zoysia here.
Part the grass along the border between healthy and damaged areas. Look for tiny black bugs with white wings. They’re small – maybe 1/5 inch – but you can see them if you look close. They hang out where healthy grass meets damaged areas.
Treatment: Insecticide labeled for chinch bugs. Water the lawn thoroughly before and after treatment. Also address any thatch buildup – that’s where chinch bugs like to hide.
Nitrogen Deficiency Causes Overall Yellowing
Sometimes it’s not spots. The whole lawn is gradually losing its green color and fading to pale yellow-green.
That’s nitrogen deficiency. Grass needs regular nitrogen for dark green color and vigorous growth. When nitrogen runs out, grass fades to yellow starting with the older leaves.
Unlike disease or pest damage, nitrogen deficiency hits the whole lawn pretty uniformly instead of creating distinct patches. New growth might still look somewhat green while older growth yellows.
Most common in spring before you’ve started fertilizing or mid-summer if you skipped your maintenance application.
Treatment: Apply nitrogen fertilizer. You’ll see greening within 7-10 days as the grass responds. For Bermuda and Zoysia here, you should be fertilizing 3-4 times during growing season to prevent this.
Dog Urine Burns Happen All the Time
If you have dogs and suddenly got bright yellow spots with dark green rings around them, that’s urine burn.
Dog urine has high nitrogen concentration that literally burns the grass. Center dies and turns yellow or brown. The outer ring gets excessive nitrogen and turns super dark green. Spots are usually 4-8 inches across, appear wherever your dog repeatedly goes.
Female dogs cause more damage because they squat and deposit concentrated urine in one spot. Male dogs spread it around more as they mark multiple locations.
Treatment: If you catch the dog urinating, flush that area immediately with water – dilution reduces damage. For existing burns, there’s no quick fix. Rake out the dead grass, add some topsoil, reseed it. Keep the dog off that area until new grass establishes.
Prevention beats treatment here. Train your dogs to go in a designated area, or get in the habit of flushing spots with water right after they urinate.
Drought Stress Shows Up in Scattered Yellow Areas
When grass doesn’t get enough water, it conserves energy by shutting down. Blades turn dull blue-green at first, then yellow, then tan as they go dormant or die.
Drought stress typically shows up first in high spots with shallow soil, areas that get more sun exposure, or sections with compacted soil where water doesn’t penetrate well. You get scattered yellow patches instead of uniform yellowing.
Grass blades fold or roll inward during drought – that’s an early warning before yellowing starts. Footprints stay visible on the lawn instead of bouncing back because the grass blades don’t have water pressure to stand back up.
Treatment: Water deeply. Drought-stressed grass recovers pretty quick once moisture returns, assuming it hasn’t been dry so long the grass actually died. Water 1 to 1.5 inches per session, once or twice weekly. Don’t do frequent shallow watering.
If certain areas consistently yellow during dry periods even with adequate watering, you’ve got soil compaction or drainage issues that need fixing through aeration.
Too Much Water Causes Problems Too
Overwatering creates issues just like underwatering. Constantly soggy soil suffocates grass roots, prevents them from absorbing oxygen. Roots start dying, grass turns yellow, eventually you get thinning and bare patches developing.
Overwatering problems typically show up in low spots where water collects, areas with heavy clay soil that drains slowly, or anywhere your sprinklers are running too frequently.
Grass in these areas stays wet for hours after watering. Soil feels squishy when you walk on it. Often you’ll smell this sour odor from anaerobic bacteria in the waterlogged soil. Not pleasant.
Treatment: Reduce watering frequency. Grass needs roughly 1 to 1.5 inches per week total, including whatever rainfall you get. Running sprinklers daily, even for short periods, keeps soil constantly wet and creates these problems.
For low spots with chronic drainage issues, you might need to regrade or install some drainage to move water away. Some people add soil to raise the grade in problem areas.
Scalping Damage From Mowing Too Low
If yellow spots appeared right after you mowed, especially on uneven ground, you probably scalped the lawn.
Scalping removes so much of the grass blade that you cut into the crown (the growing point) or expose stems that were previously shaded. Those exposed areas turn yellow, then brown. Looks awful, but grass usually recovers.
Most common on Bermuda and Zoysia during the first few mowings in spring when lawns are uneven from winter settling, or when mowing height is set too low for the grass type.
Treatment: Raise your mower height and wait. Scalped areas typically recover within 2-3 weeks as new growth emerges. For severe scalping that exposed bare soil, you might need to overseed or plug those spots.
Prevention is way easier than treatment – maintain proper mowing height for your grass type and don’t cut more than one-third of the blade height at once.
Fertilizer Burn Creates Striped or Spotted Patterns
Applied too much fertilizer? Overlapped your passes with the spreader? Fertilizer burn causes yellow or brown stripes or spots where excess fertilizer damaged the grass.
Usually appears within 24-48 hours of application. The patterns often match your spreader width or wherever you overlapped. Grass blades look burned at the tips and edges.
Similar concept to dog urine burn, but the pattern gives it away. Dog spots are random. Fertilizer burn follows your application pattern pretty clearly.
Treatment: Water heavily to dilute and flush excess fertilizer deeper into the soil. Some grass might die and need reseeding, but often it recovers with time and proper watering. Going forward, calibrate your spreader properly and be careful not to overlap passes.
Buried Debris or Severely Compacted Soil
Sometimes yellow spots appear in random areas that don’t fit any disease or pest pattern. Might want to check what’s below the surface.
Construction debris buried during home building, old tree stumps left underground, or heavily compacted soil from equipment or heavy foot traffic – all of these restrict root growth. Grass growing above these problem areas struggles and turns yellow during stress periods.
Typically these spots show up in the same locations year after year. You fix them temporarily, yellowing comes back.
Treatment: Dig down in affected areas and see what you find. Remove buried debris if that’s what it is. For compacted soil, aggressive core aeration multiple times per year helps. Worst case, you might need to excavate severely compacted areas, amend the soil, and replant.
Figure Out What You’re Actually Dealing With
Walk your lawn and look at those yellow areas closely. Ask yourself some questions:
What’s the pattern? Circular spots spreading outward? Probably fungal disease. Random and scattered? Could be drought, compaction, buried debris. Following where your dog always goes? Urine burn.
When did it appear? Suddenly during hot, humid weather? Fungal disease. Gradually over several weeks? Nitrogen deficiency or drought stress. Right after mowing? Scalping. After you fertilized? Fertilizer burn.
How’s the grass itself? Does turf pull up easily like carpet? Grubs eating the roots. Do blades look water-soaked or have lesions? Disease. Is grass just pale overall? Nitrogen deficiency.
Where is it? Low, wet spots? Drainage issues or disease. High, dry areas? Drought stress. Near pavement? Heat stress or possibly chinch bugs.
Answering these narrows down the likely causes so you can treat effectively instead of just guessing and hoping.
When You Should Call a Pro
Some yellow spot issues are straightforward DIY fixes. Apply fertilizer, adjust your watering, treat obvious grubs. Others need professional diagnosis.
If you’ve tried treatments without improvement, if yellow areas keep spreading despite your efforts, or if you honestly can’t figure out what’s causing it, get professional help. We see these problems every day and can usually diagnose causes that homeowners miss.
Fungal diseases especially benefit from professional treatment. We’ve got access to commercial-grade fungicides that work better than what you’ll find at the store. And proper diagnosis ensures you’re treating the right disease with the right product at the right time instead of wasting money on the wrong approach.
Yellow spots aren’t just cosmetic issues. They’re telling you your lawn is under stress. Identifying and addressing the cause early prevents minor problems from becoming major lawn renovation projects down the line.
Frequently Asked Questions
Why does my lawn have yellow spots after rain?
Heavy rain can trigger fungal diseases like brown patch, especially when it’s warm out. Wet grass blades sitting there for hours provide perfect conditions for fungus to infect and spread. Yellow spots that appear 3-7 days after prolonged rain are usually disease-related. Make sure you’ve got good drainage and don’t water if rain has already saturated everything.
Can yellow spots on lawn be fixed?
Yeah, most causes are treatable. Fungal diseases respond to fungicide plus cultural changes. Pest damage needs insecticide treatment. Nutrient deficiencies need fertilizer. Drought stress reverses with proper watering. The key is correctly diagnosing what’s causing it so you apply the right treatment instead of just guessing and wasting time and money.
How do I know if yellow spots are fungus or insects?
Fungal spots typically show up during humid weather. They’re circular with defined borders. Grass blades show lesions or that water-soaked look. Insect damage makes turf feel spongy. Grass pulls up easily. And you can actually find the insects – grubs, chinch bugs – by examining the soil and grass closely. Fungus spreads outward in rings. Insect damage looks more random as the pests move around feeding.
