Lawn Diseases
Gray Leaf Spot: One Name, Three Different Diseases
NC State: perennial ryegrass loses turf in a few days, St. Augustine is the most resistant host. Same pathogen — so your grass decides how worried to be.
Topic collection
Fungal Lawn Diseases
Which fungus is damaging my lawn, and how do I stop it?
Most lawn 'mystery patches' are one of a dozen fungal diseases, and they are distinguished by patch shape, blade lesions, weather and season rather than by guesswork. These guides cover identification, curative treatment, fungicide rotation and the cultural changes that stop recurrence.
12 guides in this collection ·All Lawn Diseases
Lawn Diseases
Lawn Rust: The Disease You Mow Off
Illinois Extension: the rust is removed by the mower blade. It is the one lawn disease where the treatment is a machine you already own — and a sharp one.
Lawn Diseases
Leaf Spot and Melting-Out: Too Late to Spray
Penn State: fungicides applied at the melting-out stage usually produce little improvement. Rutgers names the three causes — and all three are things you do.
Lawn Diseases
Powdery Mildew: Sunlight Is the Fungicide
NC State: sunlight inhibits growth of the powdery mildew fungus. On a lawn it is a shade reading, and the treatment is a pruning saw rather than a sprayer.
Lawn Diseases
Red Thread: The Lawn Is Telling You It Is Hungry
Penn State: in most situations red thread is not severe enough to warrant fungicide. It is a nitrogen reading — and the fix is feeding, not spraying.
Lawn Diseases
Best Lawn Fungicide: You Are Buying a FRAC Group, Not a Brand
NC State: the FRAC 11 fungicides that beat brown patch do not work well on gray leaf spot. Name the disease first — the group follows, and the brand barely matters.
Lawn Diseases
Mushrooms in Lawn: There Is Nothing to Spray
Illinois Extension: there are no recommended fungicides for controlling these species. Mushrooms are not a lawn disease — they are something buried, rotting.
Lawn Diseases
Azoxystrobin vs Propiconazole: One Misses Dollar Spot
Virginia Tech: azoxystrobin essentially has no activity against dollar spot. That one gap decides which of the two homeowner lawn fungicides you actually need.
Lawn Diseases
Dollar Spot Treatment: The Disease Nitrogen Fixes
Dollar spot is the one lawn disease caused by too little nitrogen, not too much — the exception to every other fungus guide here. The hourglass lesion confirms it.
Lawn Diseases
Lawn Fungus Identification: Rule Out 4 Impostors
Lawn fungus identification by patch pattern, blade lesion and season — starting with the four things that look like disease and are not.
Lawn Diseases
Brown Patch Treatment: Fungicide Alone Won't Fix It
Brown patch treatment needs two things: the right fungicide, and the summer nitrogen habit that caused it. Fungicide alone buys you a repeat next July.
Lawn Diseases
Snow Mold Treatment: It Grew Under the Snow
Snow mold treatment is mostly about the autumn before: gray and pink snow mold grew under the snow, so what you see in March is already finished damage.
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