A warm-season month-by-month lawn care plan for St. Augustinegrass in USDA zone 8, built on soil temperature, not the calendar.
By the TurfTrigger team · Last reviewed October 10, 2026 · How our timing models work
Zone 8 times its pre-emergent off soil temperature: spring for crabgrass, fall for Poa annua. Add your ZIP and we’ll track your ZIP’s modeled soil temperature daily and email you when our model says each window opens.
Free · Zone 8 windows are typically ~early March and ~late September to early October.
Spring pre-emergent has to go down and be watered in before crabgrass germinates. Treat soil warming toward about 50°F as the early cue and check your ZIP's spring window; do not wait for 55°F, because crabgrass can start emerging as soil warms through that range, sometimes earlier in warm spots. ZIP soil temperatures are modeled about two inches deep and averaged over several days. Calendar dates drift year to year, so go by the soil, not the date.
Only topdress or sand-level once the lawn is in active growth: soil temperatures consistently above 65°F (closer to 75°F for sand leveling). Burying the canopy before the grass can grow through it smothers it.
USDA zone 8 encodes one thing: average annual extreme minimum winter temperature. It determines grass suitability and this schedule's broad seasonal structure, but not rainfall, summer heat, humidity, soil, or how fast your spring warms up. Your ZIP's live soil temperature and GDD accumulation determine the actual week each task lands, and that week shifts every year.
We replayed TurfTrigger's alert engine, with today's rules, on archived weather from 2019 to 2025 for a st. augustinegrass lawn in each city below. Typically the spring pre-emergent text went out first in Macon (Feb 5) and last in Dallas (Feb 28). Jackson alone swung 34 days between its earliest and latest season, which is why the timing comes from your ZIP's soil readings and not a calendar date. The first frost typically arrives around Nov 14 in Birmingham and Nov 28 in Dallas.
| City | Spring pre-emergent | First feeding | Fall pre-emergent | First frost |
|---|---|---|---|---|
| Jackson, MS | Feb 22Feb 4 to Mar 10 · 7 seasons | Apr 9Apr 3 to Apr 17 · 7 seasons | Sep 21Sep 14 to Oct 17 · 6 seasons | Nov 1730-season median |
| Dallas, TX | Feb 28Feb 11 to Mar 11 · 7 seasons | Apr 6Apr 3 to Apr 12 · 7 seasons | Oct 12Sep 25 to Oct 24 · 7 seasons | Nov 2830-season median |
| Macon, GA | Feb 5Jan 27 to Feb 20 · 5 seasons | Apr 12Apr 3 to Apr 21 · 5 seasons | Sep 14Sep 3 to Sep 22 · 5 seasons | Nov 1830-season median |
| Forsyth, GA | Feb 7Jan 24 to Feb 15 · 5 seasons | Apr 16Apr 3 to Apr 20 · 5 seasons | Sep 10Sep 3 to Sep 18 · 5 seasons | Nov 2130-season median |
| Birmingham, AL | Feb 13Feb 3 to Feb 27 · 7 seasons | Apr 12Apr 3 to May 2 · 7 seasons | Sep 22Sep 13 to Oct 15 · 7 seasons | Nov 1430-season median |
Simulated dates from our current rules on historical modeled weather: replay results, not texts we sent and not observed crabgrass emergence. Each cell is the typical date, with the earliest and latest season under it; the season count is how many seasons that text went out. Spring and fall pre-emergent are the "apply now" texts; first feeding is the first nitrogen text of the year. First frost is the median date the modeled air temperature first reached 36°F in fall over the previous 30 seasons. Replays use modeled weather for each city's grid cell, not a weather station, and substitute what actually happened for the forecast a real lawn would have seen.
A one-page, fridge-ready version of this St. Augustinegrass zone 8 schedule. Free, no signup.
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St. Augustinegrass is a warm-season grass, and this schedule is tuned for USDA hardiness zone 8. It breaks dormancy and greens up once soil temperatures hold near 65°F, which is the anchor for the season's first feeding and weed-control timing. Southern zones. Extremely sensitive to certain herbicides; ensure strict database checks against grass_safety schemas.
Warm-season grass in USDA zone 8. Highly vulnerable to chinch bugs in summer heat. Requires high mowing (3.5-4"), strict Large Patch prevention in the fall, and zero verticutting.
Each of our 48 grass-and-zone schedules is generated from a per-grass agronomic profile (green-up soil temperature, mowing heights, annual nitrogen budget, disease pressure) assembled from published university-extension turf guidance, then sequenced for zone 8's season length. Timing anchors follow the same soil-temperature and growing-degree-day models our live app runs, documented on the methodology page. Key public models: MSU's GDDTracker (crabgrass GDD, Calhoun 2004) and Purdue Turf Science (broadleaf timing, Schleicher 1995).
Limitations: this is general guidance for typical st. augustinegrass lawns in zone 8, not a reading of your yard. Microclimate, soil, and each spring's weather shift the real windows by weeks, which is why the exact weeks come from live soil data, not this calendar. And the product label always wins: follow the label's rates, restrictions, and safety directions over anything here.
Apply spring pre-emergent before crabgrass germinates: check your ZIP's spring window as soil warms toward 50°F, and do not wait for 55°F. In zone 8 that is usually early-to-mid spring, but the exact week shifts every year. Track soil temperature, not the calendar.
Keep St. Augustinegrass around 2.5–3.5″ in spring and fall, raising to about 3–4″ through summer heat. Never remove more than one-third of the blade in a single mow.
St. Augustinegrass wants roughly 2–4 lbs of nitrogen per 1,000 sq ft per year. Wait until complete green-up and 65°F soil temperatures. Feed throughout peak summer growth. Cease nitrogen applications in fall.
The signature disease is Take-All Root Rot, triggered by high rainfall and stressed roots. Catching the conditions early is far easier than curing an outbreak.
Yes, zone 8 is within St. Augustinegrass's recommended range. St. Augustinegrass is a warm-season grass. It needs mild winters (zones 8–10) and won't survive hard freezes up north.