
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.

Systemic Fungicide
★★★★★ 4.5/5
our editor rating how we score4.4/5 from 14,280 shoppers at Amazon — their number, not ours.
$19–$24
Typical price · 5,000 sq ft per 10 lb bag
Affiliate links — see our disclosure. Commissions never influence verdicts.
Granular azoxystrobin with up to 4 weeks of systemic protection. The easiest effective fungicide for homeowners — spreader-applied, watered in once.
The default first response to brown patch, large patch and most common lawn fungi. Broad-spectrum, forgiving to apply, and long-lasting — rotate with propiconazole if disease pressure persists.
Product type
Systemic Fungicide
Active ingredient
Azoxystrobin 0.31% (granular)
Price range
$19–$24
Coverage
5,000 sq ft per 10 lb bag
Best for
First response to active fungal outbreaks
our editor rating
4.5 out of 5
Label read on EPA's label database
EPA Reg. No. 538-330
We opened this product's accepted label on EPA's own Pesticide Product Label System — the strongest source available for what a product is registered to do.
Full label read 2026-08-02 on EPA PPLS. Registered product name is 'Lawn Fungus Granular'; DiseaseEx is a brand name on that registration. Azoxystrobin 0.31% confirmed. Diseases on the label: Anthracnose, Brown Patch, Cool Weather Brown Patch, Fusarium Patch, Gray Leafspot, Leaf Rust, Necrotic Ring Spot, Pink Patch, Powdery Mildew, Pythium Blight, Red Thread, Rhizoctonia Large Patch, Snow Mold, Spring Dead Spot, Stem Rust, Summer Patch, Take-All Patch, Yellow Patch, Zoysia Patch. CORRECTION: our targets listed DOLLAR SPOT, and the word 'dollar' does not appear anywhere on this label — removed 2026-08-02. No article claimed it, and dollar-spot.mdx correctly cards the propiconazole product instead. 'Take-all root rot' in our targets is the label's 'Take-All Patch' (same pathogen, warm-season host name) with a fall application timing of twice, typically September onward — kept, but read as the label's wording. Note this is a MASTER label with bracketed optional text, so a specific retail bag may print a shorter disease list than the registration allows.
Where this page and the container disagree, the container wins — the label is the legal authority on rates and restrictions. How to read one yourself.
Matched against each state's actual disease, weed and pest pressure.
Application window: Bermuda and zoysia: May through August. Centipede: one light feeding, and that is the whole programme
Application window: Bermuda: light monthly feedings May–September, plus iron for alkalinity yellowing
Application window: Bermuda and zoysia: May through August. Fescue in the north: September and October only
Application window: Fescue: October–November and March–April; Bermuda: May–August
Application window: UConn's two dates are May and early September, with a third in June only if you bag the clippings — 2 lb of nitrogen per 1,000 sq ft a year if clippings are returned, 3 lb if removed, and never more than 1 lb of soluble N at once. Nothing before April 15 or after mid-October
Application window: Delaware is a soil-test state by law and by Extension practice — the University of Delaware declines to publish blanket rates and tells you to follow the report. The autumn feeding is the one that carries a transition-zone lawn; 3 DE Admin. Code 1204 sets per-application limits, no-application periods and setbacks on top of that
Application window: April–May and September–October (check local summer blackout ordinances)
Application window: Bermuda: monthly light feedings from full green-up (late April) through August
Application window: Rate follows species: hybrid bermudagrass has the highest requirement, zoysia, St. Augustine and seashore paspalum are intermediate, and centipede needs the least. Because growth never stops and the soils leach, the pattern is lighter and more frequent rather than two or three big applications — and seashore paspalum wants nitrate-N rather than ammonium-N during establishment
Application window: UI publishes a five-slot schedule for a medium-to-high maintenance bluegrass lawn: half to one pound of nitrogen per 1,000 sq ft in mid-March or April, one pound in early May or June, NOTHING in July or early August, one pound in mid-August or September, and one to two pounds in early October or November with the higher rate optional. A season total runs anywhere from 0.5 to 5 lb depending on the quality you want; a low-maintenance tall fescue lawn sits at 2 to 4 lb
Application window: Labor Day and Halloween feedings do 80% of the work; optional light Memorial Day application
Application window: Purdue's five slots: up to 0.75 lb slow-release in April, 0.75–1.0 lb in May, 0.75 lb in July on irrigated lawns only, 1 lb in September, and 1.5 lb of fast-release urea in November after the final mowing while the grass is still green
Application window: Early September and late October — the fall programme carries an Iowa lawn
Application window: K-State splits this by species rather than by month. Tall and fine fescue: about 1 lb of nitrogen per 1,000 sq ft, applied in autumn. Zoysia: 1 to 1.5 lb, in early summer. Buffalograss: the least of any Kansas lawn grass — 1 lb in early June improves colour and density, and more than that makes it weedy
Application window: Fescue and bluegrass: September and late October. Check the soil test before buying anything with a middle number — Inner Bluegrass limestone soils routinely test phosphorus-sufficient already
Application window: St. Augustine takes at least 1 lb of nitrogen in June and again in early to mid-August, up to about 3 lb a year, applied from midspring to midsummer
Application window: UMaine is specific and restrained: no more than two pounds of nitrogen per 1,000 sq ft a year, and if you feed once, do it between August 15 and September 15. Any remainder goes down in May after spring green-up, not before it
Application window: Tall fescue feeds September and late October — and the state's blackout starts November 16, which is earlier than most neighbours
Application window: Late spring and early September, with a late-October application where the rules allow — the season is short enough that timing matters more than rate
Application window: April through October, and MSU is specific that applications should go down before November — later nitrogen leaches over winter rather than feeding the grass
Application window: The University of Minnesota scales nitrogen by maintenance level AND soil organic matter: a low-maintenance unwatered lawn takes a single September application of 0.5–1 lb, while a watered lawn with clippings removed takes four — August, September, early October and May–June — and no single application should exceed 1 lb per 1,000 sq ft
Application window: Bermuda: May through August. Centipede: one light feeding a year and nothing more
Application window: Fescue: September and late October, with a light spring feeding at most; zoysia and bermuda: May through August
Application window: UNL publishes dates, not seasons, for cool-season lawns: April 15–25 at 0 to 0.5 lb of nitrogen per 1,000 sq ft, May 25–June 5 at 0.5 to 0.75, August 25–September 5 at 0.5 to 0.75, and October 15–November 1 at 0 to 0.25. Western Nebraska shifts one to two weeks later in spring and one to two weeks earlier in autumn. Buffalograss and zoysia get one application, May 5–15, at about 0.5 lb — and buffalograss should never exceed 2 lb a year
Application window: Bermuda in the south: May through August. Tall fescue and bluegrass in the north: spring and early autumn
Application window: One to two pounds of nitrogen per 1,000 sq ft a year is UNH's range for a home lawn — lower than the coastal states south of here. The last application of the year should be down before September 15 in northern New Hampshire and October 1 in the south
Application window: Legally March 1 – November 15 for homeowners (professionals get to December 1), and capped at 3.2 lb of nitrogen per 1,000 sq ft a year — weight it to September and October
Application window: New establishment gets 0.5 to 0.75 lb of nitrogen per 1,000 sq ft every other week for six to eight weeks. After that the calendar follows the grass, not the state: cool-season lawns in the north feed spring and autumn, warm-season lawns in the south feed through the warm months and stop well before dormancy
Application window: September is the one application Cornell recommends at every level of lawn quality; May, June and October are optional extras, and no application may exceed 1 lb of nitrogen per 1,000 sq ft
Application window: Fescue feeds in fall: September, October and late November — never in summer
Application window: September and early November (winterizer) carry the lawn; optional light feeding late May
Application window: Bermuda and zoysia: May through August. Buffalograss wants almost none — feeding it is how people lose it to weeds
Application window: Light and frequent through spring and autumn west of the mountains; east-side lawns follow a shorter, more conventional cool-season programme
Application window: September and late October, and the state closes the window on December 15 — the tightest legal autumn sequence of any state here, because the rate caps limit how much can go down in each of those passes
Application window: Late spring and early September, with the September application doing most of the work. The Water Resources Board's statewide guidance asks for moderate rates and never above label — and municipal ordinances in the bay towns cap it far below that
Application window: Centipedegrass takes nitrogen in May and once in late summer only, 1–2 lb a year total; the last application goes down before August 15 in the Upstate and before September 1 on the coast
Application window: Fescue: September through November; Bermuda and zoysia: May through August
Application window: Late April after full green-up, June, and early September
Application window: Late spring and early September, kept modest — pushing growth in a place where every inch of it is irrigated costs water as well as fertilizer
Application window: Late spring and late August to early September, with the late-summer application carrying the year. Get it down early — the growing season closes fast north of Rutland
Application window: Cool-season lawns take 2.0–3.5 lb of nitrogen a year across September, October, November, April and May at 0.5–0.7 lb a month; bermuda and zoysia are fed only between April 1 and August 15
Application window: Mid-May only if the lawn is thin or yellow, then September–October; slow-release synthetic as late as mid-November
Application window: Autumn carries a transition-zone lawn, so the September feeding is the year's most valuable. Nitrogen is the one nutrient required regardless of what the test says; phosphorus, potassium and lime should all follow the report, which in West Virginia usually asks for lime
Application window: About 2 lb of nitrogen a year in total: roughly 1 lb at the second mowing in spring and 1 lb between September 1 and 15, with any summer application kept under 1 lb and only on irrigated lawns
Common questions
Scotts DiseaseEx Lawn Fungicide typically runs $19–$24, covering 5,000 sq ft per 10 lb bag.
Scotts DiseaseEx Lawn Fungicide targets Brown patch, Large patch, Gray leaf spot, Snow mold, Take-all root rot, Spring dead spot, among others.
Azoxystrobin 0.31% (granular), registered under EPA Reg. No. 538-330.
Costlier per treatment than propiconazole concentrates
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Lawn Diseases
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 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 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.

Lawn Diseases
Spring dead spot and summer patch attack roots, not leaves — so they mimic drought, shrug off leaf sprays, and return to the same spot bigger each year.

Grass Types
St. Augustine grass care: mow high, watch for chinch bugs, and know it cannot be seeded — only sod, plugs or sprigs. Plus the herbicides that damage it.

Grass Types
St. Augustine vs zoysia comes down to two questions: how much shade, and how much foot traffic. One tolerates each — and they are not the same grass.

Lawn Diseases
Two look-alikes get treated instead. Texas A&M's field test separates them in five minutes, and the fungicide only works before you can see the damage.

Lawn Diseases
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
Flooding moves the pathogen, stresses the plant and leaves the leaf wet. The hour thresholds that trigger Pythium and brown patch, and why nitrogen cuts both ways.

Lawn Diseases
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
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
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.
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