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What's Wrong With My Lawn?
Pick what you're seeing — brown spots, whole-lawn browning, dead patches, or yellowing — and add a detail or two. You'll get a ranked shortlist of the likely causes for your situation, each with the tell-tale sign that sets it apart and the safe first move, plus a link to the full guide. Identify before you treat: most summer browning is fixed by watering and mowing, not chemicals.
Add a detail to narrow it (optional, sharpens the answer)
Most likely causes
For a lawn with brown spots or patches, start here
Ranked for what you told us, most likely first. Each cause shows the tell-tale sign that sets it apart and the safe first move — then links to the full guide. Add a detail above to sharpen the order.
Fungal disease
How to tell: Roughly circular brown or tan patches that appear overnight, often with a darker ring, worst in hot, humid weather or after evening watering.
Safe first move: Water in the morning and improve airflow, then identify the disease before feeding or spraying — the fertility fix differs by disease: ease off nitrogen for brown patch and large patch, but a light, balanced feeding actually helps dollar spot and red thread, which are worse in underfed turf.
Fungal disease: the full guide →Grubs
How to tell: Spongy turf that lifts like loose carpet because the roots are chewed off, irregular dead patches, and birds or skunks digging at night.
Safe first move: Tug-test the edge of a patch; if it peels back and you find white C-shaped larvae, confirm the count before treating.
Grubs: the full guide →Dog urine or a spill
How to tell: Small, sharply defined dead spots — often ringed by lush, extra-green grass — in the same places a pet uses or where fertilizer or fuel was spilled.
Safe first move: Water the spot well to dilute it; these small areas are repaired once the cause is managed — reseeded in fall for most lawns, or plugged/sodded for St. Augustine.
Dog urine or a spill: the full guide →
📷 In the app · Still not sure?
Snap a photo for an AI diagnosis — in the YardLedger app
Photo diagnosis is a free in-app feature (this page is a symptom-based guide, no photo needed). A photo narrows the possibilities rather than settling them: in the app, stand over the problem spot, snap a picture, and YardLedger’s assistant reads it in the context of your yard — your grass, your history, your local weather — to rank the likely causes and tell you the next thing to check. Many lawn problems look alike in a photograph, and several can only be told apart at the crown and roots or under magnification, so treat the ranking as triage: pull a plug at the edge of the damage, check soil moisture and sprinkler coverage, and look for insects before you treat anything. A diagnostic lab or your local cooperative extension office is what actually confirms a pest or disease from a sample — worth doing before any pesticide — and the product label is always the final authority on any treatment.
Create a free account to use photo diagnosisSafety first
This is triage, not a diagnosis: it ranks what is likely from what you told us, and confirming which one it actually is takes a look at the lawn itself. Identify the cause before you treat it — most summer browning is fixed by watering and mowing, not chemicals, and a pesticide aimed at the wrong problem just adds cost and risk. Before any pesticide, get the identification confirmed: pull a plug at the edge of the damage and check the crowns and roots, look for insects in the thatch, and send a sample to your state diagnostic lab or cooperative extension office if it is not obvious. Several lawn diseases are indistinguishable without magnification. When a product is warranted, the label is the legal authority on what it's for, how much to use, and how to use it safely. Always read and follow the product label — it is the legal authority on rates, timing, and safety. These windows are regional estimates, not a prescription; defer to the label and your local extension office.
Common questions
- Why is my grass turning brown?
- Most summer browning is drought or dormancy — the lawn protecting itself in heat — and it greens back up with water or cooler weather. But brown can also mean fungus, grubs, chinch bugs, scalping, or fertilizer burn, and each has a different fix. The pattern (even vs. patchy vs. ringed), the timing, and what you did recently narrow it down fast — which is exactly what this tool does.
- What causes brown spots in the lawn?
- Distinct brown spots (as opposed to an evenly browning lawn) usually point to a specific cause: a fungal disease (often circular, with a smoke-ring edge), grubs (spongy turf that lifts like carpet), chinch bugs (spreading in hot, dry spots), dog urine or a spill (small, sharp-edged), or scalping. Identify the cause before you treat — a product aimed at the wrong problem just adds cost and risk.
- Is my grass dead or dormant?
- Give a browned patch a firm tug. If it resists and the crowns at the soil line are firm and off-white, it's alive and dormant — be patient and water. If it pulls out in a loose handful with dry, brown, crumbly crowns, that patch is dead and will need repair — reseed a cool-season lawn in fall, or plug/sod a warm-season grass like St. Augustine during warm growth. Most brown summer lawns are dormant, not dead.
- Do I have lawn fungus, grubs, or drought stress?
- Drought browns evenly, worst in the sun, and perks up a day or two after a deep watering. Fungus shows up as roughly circular patches, often overnight in hot, humid weather. Grubs leave spongy patches that peel back like loose carpet because the roots are chewed off. Tell them apart before treating — this tool ranks the most likely one for your symptoms, and each links to a full guide.
- Why does my lawn have brown patches?
- Round patches that appeared overnight in humid heat are the classic sign of fungal disease; spongy patches that lift like carpet are grubs; spreading patches in the hottest, driest spots are chinch bugs; small, sharp-edged dead spots are dog urine or a spill; and striping right after a feeding is fertilizer burn. Read the shape, location, and timing before you reach for any product.