St. Augustinegrass: Cultivar Guide and Complete Management for the Southeast
Most people who end up with St. Augustinegrass didn’t choose it — they inherited it. You bought the house, there was SA in the yard, and you’ve been applying whatever lawn care instincts you brought from somewhere else. If the lawn is struggling, that’s usually why.
Here’s the honest framing: St. Augustinegrass (Stenotaphrum secundatum) is a higher-maintenance grass relative to zoysia or centipede. It has a higher nitrogen demand, it’s the preferred food source of the most destructive lawn pest in Florida, it can’t be started from seed, and it’s sensitive to the broadleaf herbicides that work fine on every other common warm-season grass. None of that makes it wrong for your site — in the right situation (coastal, Zone 8–10, warm and humid, decent shade) it’s genuinely the best fit. But “it’s everywhere around here” isn’t a management plan.
If you’re comparing SA to zoysia before making a choice, the cultivar breakdown for zoysia is at frugallawnguy.com/zoysia-cultivar-guide. This article is for people who already have SA, or who’ve decided that’s the grass for their site.
What Makes St. Augustine Different
SA spreads by above-ground stolons only — no rhizomes, no seeded cultivars. Every cultivar requires sod, plugs, or sprigs. It has the best shade tolerance of any warm-season grass (most cultivars need 4–6 hours of direct sun), a high nitrogen demand (2–6 lbs N per 1,000 sq ft depending on region, per UF/IFAS LH010), and it’s the preferred food source of the southern chinch bug (Blissus insularis) — the pest that kills SA lawns at scale across the Southeast.
The most common management mistake: applying 2,4-D. Most broadleaf weed killers — Ortho Weed B Gon and most generics — contain 2,4-D or dicamba, or both. Both damage SA: leaf curl, stem injury, dieback. Read the grass species label on every product before it touches an SA lawn.
Cultivar Guide
Floratam
The default SA — dominates the market because most sod farms produce it and it’s the cheapest pallet price. Released in 1973 with chinch bug resistance that UF/IFAS confirms “has largely been lost over time.” Coarse texture, dark green, fails below 6 hours direct sun, poor cold tolerance. Sensitive to atrazine above 85°F. Reasonable choice for deep south Florida with full sun. For anyone north of Lake Okeechobee, with chinch bug history, or needing shade performance — better options exist at manageable premiums.
Palmetto
Best all-around cultivar for most SA homeowners outside deep south Florida. Very good cold tolerance, very good shade tolerance, and the best chinch bug resistance of any widely available standard cultivar (UF/IFAS EDIS Table 1). Medium texture, lighter green, mow at 3–4 inches. Where I’d point most people starting fresh.
Seville
The shade specialist. Very good shade tolerance, dense growth habit, mows at 2–2.5 inches (dwarf type). Trade-offs: thatch prone, shallow roots, susceptible to chinch bugs and sod webworms. Right for lawns with 3–4 hours of filtered sun in Zone 9 or warmer. Cold sensitivity rules it out at the upper end of SA’s range.
Raleigh
The cold hardiness standard — go-to for north and northwest Florida, lower coastal Georgia, anywhere SA is pushing its northern limits. Weaknesses: highly susceptible to gray leaf spot, poor chinch bug resistance. Right call in Zone 8a–8b where cold winters are the binding constraint.
Viridian (formerly ProVista)
Rebranded by Scotts in 2025 with cold tolerance from Raleigh genetics. The core trait: first glyphosate-tolerant turfgrass commercially available — apply Roundup to kill weeds without killing the lawn. Also grows at roughly half the rate of Floratam. Not a cost-sensitive recommendation — premium pricing and limited availability are real.
Captiva
UF’s answer to Floratam’s lost chinch bug resistance. Best chinch bug resistance of any commercially available SA cultivar. Dwarf type, 2–3 inch mowing height, dark green, good cold and shade tolerance. Florida-focused production.
CitraBlue
Newest UF/IFAS release (2018). Blue-green color, denser growth, very good shade tolerance, more drought tolerant than Floratam and Palmetto per UF/IFAS. Mow at 2–3 inches. The direction UF/IFAS is pointing the market.
Quick Cultivar Reference
| Who you are | The pick | Primary reason |
|---|---|---|
| Default / replacing Floratam, good sun | Palmetto | Best all-around outside deep south FL |
| Chronic chinch bug history, FL | Captiva | Best available chinch bug resistance |
| Significant shade, Zone 9+ | Seville | Fine texture, dense, very good shade |
| Cold concern, upper Gulf / north FL | Raleigh or Palmetto | Cold hardiness is the binding constraint |
| Want simpler weed management | Viridian | Glyphosate tolerance, slower growth |
| Want current UF genetics, FL | CitraBlue | Drought tolerance, shade, newer disease data |
| Budget, deep south FL, full sun | Floratam | Cheapest, most available |
Mowing and Fertility
Standard cultivars (Floratam, Raleigh, Palmetto, CitraBlue): maintain at 3.5–4 inches with a rotary mower. Dwarf cultivars (Seville, Captiva): 2–2.5 inches. Never remove more than one-third of the blade in a single pass — SA crowns don’t recover from a hard scalp the way bermuda does. Sharpen rotary blades monthly; dull blades shred the wide SA leaf and leave a brown cast.
For nitrogen: 2–4 lbs N per 1,000 sq ft in north Florida, 4–6 lbs in south Florida (UF/IFAS LH010). Gulf Coast Georgia and SC coastal, treat as north Florida. First application no earlier than mid-April.
Iron: SA on high-pH soils or alkaline irrigation water yellows from iron deficiency that looks like nitrogen deficiency. If you’ve applied nitrogen and the lawn is still yellow, chelated iron (Southern Ag Chelated Liquid Iron, ~$10–15 for 16 oz) as a foliar spray is the right next move.
Chinch Bugs: The Primary Threat
Damage looks like irregular yellowing in hot, dry, full-sun areas — along sidewalks, adjacent to structures — spreading outward as the population moves to fresh grass. This distinguishes chinch bugs from TARR (which appears first in shadier areas) and drought (which stresses the lawn more uniformly).
Flotation diagnostic: Remove both ends from a metal coffee can, push it 3 inches into the soil at the margin of a yellowing area, fill with water for 5 minutes. Chinch bugs float to the surface. Run at multiple spots around the damage edge.
Treatment: Generic 7.9% bifenthrin concentrate (Bifen IT, ~$20–30 for 32 oz, ASIN B0CMJG4JJD) — same active as Talstar P at a fraction of the price. Water lightly before application. If bifenthrin doesn’t hold, rotate to imidacloprid (Dominion 2L) — some Florida populations have developed pyrethroid resistance, and imidacloprid’s systemic action handles those.
🔗 Buy: Bifen IT (bifenthrin 7.9%) 32 oz — ~$20–30
Not sure if it’s chinch bugs, drought, or something else? The triage article walks through how to tell them apart.
TARR and Atrazine
TARR (Take-All Root Rot) is the most frequently misdiagnosed problem in SA lawns — called drought stress, called chinch bugs. The diagnostic tell: pull an infected stolon. Roots are short, black, and rotted. Chinch bugs leave roots intact; TARR destroys them.
Treatment: 1 bale (3.8 cubic feet) of sphagnum peat moss per 1,000 sq ft. Sphagnum peat pH of ~4.4 suppresses the TARR pathogen directly. Texas A&M field research confirmed peat moss outperformed manure compost for TARR suppression. Caveat: alkaline municipal water in Florida gradually neutralizes the effect — reapply in spring. Fungicide applications (azoxystrobin, propiconazole) must be preventive, about one month before when your lawn historically shows TARR. Curative applications after symptoms appear are limited.
Atrazine is the cornerstone selective herbicide for SA — controls dollar weed, chickweed, clover, oxalis, spurge, and more. Consumer products (Hi-Yield Atrazine, ~$15–20 for 32 oz, ASIN B016TQFPQ2; Southern Ag Atrazine on St. Augustine Grass, ~$12–18, ASIN B0052MZBYQ) are general-use, no license required. Do not apply above 85°F on Floratam. Do not apply to drought-stressed grass. For timing guidance, this article covers the seasonal sequencing.
🔗 Buy: Hi-Yield Atrazine Weed Killer 32 oz — ~$15–20
🔗 Buy: Southern Ag Atrazine St. Augustine Weed Killer 32 oz — ~$12–18
Top 3 Anti-Patterns
Scalping in spring. The instinct is to “get the lawn looking clean” after winter. SA crowns don’t recover from scalping the way bermuda does. Cut it hard in March and you’ve set the stage for a weak stand heading into peak chinch bug season. Keep it at the correct height year-round.
Applying weed-and-feed without checking compatibility. Many weed-and-feed products contain 2,4-D, which damages SA. Read the grass species label every single time, including on products you think you already know.
Overwatering in shade. The problem in a shaded area is usually light, not water. Adding irrigation to compensate for thin, stressed grass in shade increases TARR pressure without solving the underlying deficit. Address the light deficit first — prune trees before you add water or re-sod.
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