Second spray now?—late September

Thirty-two days after Labor Day is when warm-season DIY threads flip from “did cool fronts open the first fungicide window?” to “I already sprayed—do I need the follow-up this weekend?” NC State’s spring-dead-spot program is explicit: after the first fall application, make a second about 21–28 days later while soils stay above roughly 55 °F, and water product into the root zone. Large patch runs a parallel homeowner story—two well-timed fall apps often cover the season, with Clemson’s South Carolina tables spacing the second spray about three weeks after the first once soils near ~70 °F. Labor Day 2026 was Monday, September 7; a first spray that weekend is now inside (or one weekend away from) the classic follow-up band—while Deep South lots that never opened Path A still belong on the first-spray forks, not a panic re-dose.

This page is the late-September warm-season fall fungicide second-app execute fork—the handoff after Spray SDS now?—late September, Oct 15 spray?—early October large patch, Spray now?—late September large patch, First spray?—Labor Day large patch, the SDS fall timing checklist, and the large-patch fall timing checklist. It sits beside Seed rye now?—early October bermuda, Stage desert rye?—early October, Seed rye?—late September bermuda, Keep scouting?—late September armyworms, warm-season N stop, and winterizer myths. It is not a remote diagnosis and not a fungicide prescription. Confirm chronic patches, product choice, and reapplication intervals with county extension or a diagnostic clinic. Always follow the current product label. Map treated polygons with the free lawn area calculator and scale carrier volume with the liquid / sprayer calculator.

Key takeaways

• NC State spring dead spot: start when fall soils drop to about 70 °F; pathogens most active about 75–60 °F (Oklahoma State infection optima near ~65 °F); make the second application about 21–28 days later while soils stay above roughly 55 °F (putting-green trials often favor ~21 days after a rapid cool-down); irrigate with at least ⅛ in. immediately so product reaches roots/rhizomes/stolons; map spring circles for spot treatment.
• Clemson HGIC 2153 (SDS): fungi most active when soils are below 70 °F until about 50 °F; homeowner calendars often stack near October 1, mid-October, and late October (about one month before dormancy)—Deep South Path C honesty still applies if you never opened first spray; granular home products often need about ½ in. water-in; propiconazole may slightly delay spring green-up; skip DNA PRE on recovering spring circles.
• NC State large patch: centipede / St. Augustine often start near ~80 °F for 5+ days; zoysia near ~70 °F for 5+ days; two well-timed fall apps may provide season-long control; severe sites may repeat about every 4–6 weeks while soils stay above ~50 °F; apply in at least 2 gal / 1,000 sq ft (3+ or light watering-in often helps)—sheath/thatch contact, not SDS-style root flooding alone.
• Clemson large-patch SC tables: once soils consistently near ~70 °F, schedule the second fungicide about 3 weeks after the first (regional average first dates often land mid–late October—do not invent an Upstate second app for a coastal lot that never sprayed).
• DIY late-September job: pick Path A (bermuda SDS first spray ~21–28 days ago + soils still above ~55 °F → second SDS root-zone app), Path B (large-patch hosts first spray ~3–4 weeks ago or label interval + soils still conducive → second sheath app), Path C (first spray not yet / Deep South October lag → stay on first-spray forks), or Path D (no history / already finished two apps / soils below stop cues → skip)—not “re-spray because Labor Day already passed.”

Why this late-September week confuses people

Cue that tempts the wrong Saturday	What extension is saying	DIY correction
“Labor Day spray was enough—put the jug away forever”	SDS and large patch both lean on a second fall pass while the infection window is open	Open the journal; count days since first spray
“Neighbor’s zoysia jug = my bermuda second app”	Large patch sheath disease ≠ SDS root infection; carrier habits differ	Path A vs Path B by grass + disease
“Soils already cold—spray anyway”	SDS second apps stop when soils fall below ~55 °F (NC State); severe large-patch sites stop near ~50 °F	Path D if the stop cue already hit
“Never sprayed—copy the second-app calendar”	Second apps assume a real first spray on a soil-temp streak	Path C → late-September SDS / large patch
Soft winterizer N “for hardiness” between apps	Soft late N amplifies SDS / large patch / winter injury	Hold N; see winterizer myths
Same hose-end mist for both diseases	SDS wants root-zone water-in; large patch wants sheath coverage volume	Match delivery to Path A vs Path B

Cool-season late-September seed and nitrogen readers should stay on Still seed?—late September frost and Pulse now?—mid-September seed—this page is the warm-season follow-up fungicide execute only.

Side-by-side: Path A / B / C / D

Path	What you see this week	Late-September move
A — SDS second app	Bermuda-dominant stand; mapped spring dead circles; first labeled SDS spray already on the journal about 21–28 days ago (often a Labor Day / early-September Path A); mid-morning soil log still above ~55 °F (NC State keep-spraying cue)	Second labeled SDS preventive on the same history polygons; water in ≥⅛ in. (or label high-volume theme); journal EPA reg. no. + date; stop further fall SDS apps if soils drop below ~55 °F
B — Large-patch second app	Zoysia / St. Augustine / centipede history polygons; first labeled large-patch spray about 3–4 weeks ago (Clemson ~3 weeks; NC State two-app / label 14–28 day themes—read your bag); soils still above ~50 °F on severe-site calendars, or your label interval is due	Second labeled large-patch preventive with ≥2 gal / 1,000 sheath/thatch coverage (3+ or light water-in often helps); alternate FRAC groups when Clemson/homeowner tables call for it; journal the date
C — Still need first spray	History exists, but no honest first spray yet; soils never crossed your start band; Deep South / Clemson-style October calendars still waiting	Do not invent a “second” app—open late-September SDS or early-October Clemson large patch / late-September large patch / Labor Day large-patch first spray
D — Skip	No mapped disease history; already completed two well-timed fall apps; soils below SDS ~55 °F or large-patch ~50 °F stop cues; wrong host (bermuda copying a zoysia jug, or vice versa); rye-only color project with no disease history	Culture and map only; keep soft N off; leave rye / PRE on their own forks

The late-September second-app fork (10 steps)

1. Confirm grass and disease before you open the jug. Bermuda spring circles → SDS Path A conversation. Zoysia / St. Augustine / centipede orange sheath rings → large-patch Path B. Mixed lots → split programs. Soft black roots under yellow centipede → take-all / decline culture, not a calendar re-dose.
2. Open the journal—count days since the first spray. Path A wants about 21–28 days (NC State). Path B wants about 3–4 weeks or the label interval (Clemson ~3 weeks; many NC State product tables list 14–28 days). No first-spray date → Path C, not Path A/B.
3. Re-check soil temperature—the follow-up still needs an open window. Place a soil thermometer at about 2 in (or your bulletin’s 0–4 in average). SDS Path A: keep going while soils stay above ~55 °F. Large-patch Path B severe sites: NC State themes keep repeating while soils stay above ~50 °F. Below the stop cue → Path D.
4. Match delivery to the disease. SDS Path A: product into roots—NC State ≥⅛ in. water-in immediately (granular home labels often ~½ in. per Clemson). Large-patch Path B: sheath/thatch contact—≥2 gal / 1,000 carrier (3+ or light watering-in often helps). Do not copy one Saturday habit onto both diseases.
5. Lock the nitrogen stop. Soft late N between apps amplifies both diseases and winter injury (NC State ~6 weeks before dormancy; Clemson Aug 15 / Sep 1 themes). Hold winterizer bags with N—see winterizer myths.
6. Rule out look-alikes that still share the curb view. FAW chew fronts → Keep scouting?—late September armyworms. Carpet-lift → white-grub Labor Day last-call. Bone-dry south slopes with firm white crowns → water and culture (dormant vs dead).
7. If Path A execute: choose a product that lists spring dead spot / bermudagrass on the current label. Prefer the same mapped polygons as the first spray when practical (NC State cost theme). Scale volume with the liquid / sprayer calculator after you map treated area. A calibrated backpack sprayer plus a measuring cup keeps rates honest. Water in; confirm the root zone with a soil moisture meter; measure irrigation with a lawn rain gauge.
8. If Path B execute: choose a product that lists large patch / Rhizoctonia on your grass. Clemson homeowner tables often ask single-AI products to alternate groups between apps—read the current sheet. Deliver ≥2 gal / 1,000 to the sheath zone. Granular labels that want watering-in still need measured inches—not a hope that dew invents coverage.
9. If Path C: keep logging; hold soft N; stage chemistry on the first-spray pages—do not invent a follow-up from the calendar alone. Clemson SDS homeowner examples near October 1 and Clemson large-patch SC averages mid–late October are regional planning aids, not a national Saturday.
10. Journal the fork. Log species, disease, Path A/B/C/D, first-spray date + days elapsed, multi-morning soil temps, mapped sq ft, product name + EPA reg. no., carrier gallons / 1,000 or water-in inches, and whether the soils-above-~55 °F / ~50 °F stop cue already hit. Note rye overseed polygons separately (rye staging). That record stops next year’s “we always double-spray the last weekend of September” reflex.

Browse staging gear when the yard actually needs it: soil thermometer garden, lawn rain gauge, soil moisture meter lawn, measuring cup ml oz, backpack sprayer lawn, lawn fungicide spring dead spot bermuda, lawn fungicide large patch, propiconazole lawn fungicide, azoxystrobin lawn fungicide, lawn care notebook. Prefer a written first-spray date and soil log over hoping Labor Day invents the right follow-up week.

Timing cues side by side

Source theme	Late-September read	DIY translation
NC State SDS second app	21–28 days after first while soils stay above ~55 °F	Path A gate for Labor Day / early-Sep first sprays this week
NC State SDS delivery	≥⅛ in. water-in immediately	Root-zone honesty—not leaf mist
Clemson HGIC 2153 SDS calendar	Often Oct 1 / mid / late Oct (~one month before dormancy)	Path C if first spray never landed on coastal / Deep South lots
NC State large patch two-app theme	Two well-timed fall apps often enough; severe sites 4–6 weeks while soils >~50 °F	Path B interval honesty
Clemson large-patch SC tables	Second app ~3 weeks after first once soils near ~70 °F	Count weeks; do not copy Upstate dates onto Charleston
Carrier habits	SDS root-zone vs large-patch ≥2 gal / 1,000 sheath	Path A ≠ Path B Saturday
Soft late N	Amplifies both diseases	Hold between apps

Optional culture still beats another jug: keep irrigation on fall cutback themes, finish thatch/drainage plans only while turf still grows (thatch assessment), and leave winter weed PRE / rye color-overseed on their own late-September forks.

What a homeowner can still accomplish this week

Assessment

• Confirm grass + disease; open the first-spray journal date; re-check multi-morning soil temps against stop cues.
• Separate SDS root-zone jobs from large-patch sheath jobs before shopping.
• Write Path A/B/C/D before the fungicide aisle.

If Path A

• Same mapped SDS polygons → labeled spring-dead-spot product → ≥⅛ in. water-in → journal → watch soils vs ~55 °F.

If Path B

• Same mapped large-patch polygons → labeled large-patch product → ≥2 gal / 1,000 sheath coverage → journal → watch soils vs ~50 °F / label interval.

If Path C

• First-spray soil-temp execute only—no invented follow-up.

If Path D

• Culture and map; hold soft N; skip the jug.

Journal checklist

• Grass species by zone + disease (SDS vs large patch)
• Path A/B/C/D chosen this week
• First-spray date, product, EPA reg. no., and days elapsed
• Multi-morning soil temps (depth + time) vs ~55 °F / ~50 °F stop cues
• Second-spray product + EPA reg. no. (if Path A/B)
• Carrier gallons / 1,000 or water-in inches
• Mapped sq ft treated
• Soft N stop date already used this season
• Any rye / PRE polygons kept separate from disease polygons

Use the Lawn Care Journal app to keep the late-September second-app fork honest. Optional in-app Assistant is educational only—not a fungicide recommendation for your county.

Further reading

• Spray SDS now?—late September
• Spring dead spot bermudagrass fall fungicide timing
• Oct 15 spray?—early October large patch
• Spray now?—late September large patch
• First spray?—Labor Day large patch
• Fall large patch timing checklist
• Soil-temp logging — large patch vs spring dead spot
• Warm-season nitrogen stop
• Warm-season winterizer myths
• Seed rye?—late September bermuda
• Keep scouting?—late September armyworms

Late September needs a written first-spray date and an open soil-temperature window for the warm-season follow-up jug—not a hope that Labor Day invents a second Saturday for every county.

Sources

1. Kerns, J., Butler, L., & Hampy, H. (NC State Turf Pathology). Time to Treat for Spring Dead Spot & Large Patch (Sep 23, 2020; updated Nov 27, 2024)—SDS fungicides when fall soils drop to 70 °F; pathogens most active 75–60 °F with Oklahoma State optimal infection near 65 °F; second application 21–28 days later until soils fall below 55 °F (trials often favor ~21 days after a rapid cool-down); irrigate with at least ⅛ in. immediately; map spring symptoms for spot treatment; large-patch species clocks and carrier-volume themes summarized on the companion NC State large-patch page.
2. Butler, L., & Kerns, J. (NC State Extension). Large Patch in Turf (reviewed Dec 16, 2019)—centipede / St. Augustine preventive starts when soils decline to about 80 °F for 5+ consecutive days; zoysia near about 70 °F for 5+ consecutive days; two well-timed apps may provide season-long control; severe sites repeat about 4–6 weeks while soils stay above ~50 °F; ≥2 gal / 1,000 sq ft carrier (3+ or ~⅛ in watering-in often helps); map spring areas for fall spot treatment.
3. Williamson, J. (Clemson Cooperative Extension HGIC 2153). Spring Dead Spot (updated Aug 21, 2025)—fungi most active when soils are below 70 °F until about 50 °F; stop N after August 15 Upstate / September 1 coast; start fungicides about one month before dormancy (SC homeowner examples often Oct 1, mid-October, late October); granular products often need about ½ in. water-in; propiconazole may slightly delay spring green-up; skip DNA preemergents on recovering dead patches.
4. Clemson HGIC. Large Patch Disease Control in Warm Season Lawns—initiate fall fungicide treatments once soils drop to about 70 °F; SC multi-year average tables place first apps by region and schedule the second about 3 weeks later; spring follow-up at green-up; homeowner granular tables note watering-in (about ½ inch themes) and FRAC-group alternation for single-AI products.
5. Kerns / NC State Turf Pathology. Fall Into Warm-Season Disease Prevention—SDS second application 21–28 days after the first; root-zone irrigation theme of at least ⅛ in.; large-patch September cool-down framing with species soil-temp clocks.

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Related reads: Spray SDS now?—late September, Oct 15 spray?—early October large patch, Spray now?—late September large patch, First spray?—Labor Day large patch, Seed rye now?—early October bermuda, Stage desert rye?—early October, Seed rye?—late September bermuda, Still seed?—late September frost, Fescue weekend?—Georgia October, Still seed?—early October, Stage dormant seed?—late September, Stage October N?—late September, Pulse now?—early October seed, Feed now?—early October, Still do what?—October culture, Keep scouting?—late September armyworms, Apply now?—mid-September winter weed PRE, Warm-season winterizer myths, Stop mowing?—early October, Blow out now?—early October, Mulch weekly?—early October leaves, Stage spray?—early October henbit.

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