LawnByCounty

Lawn Care Guide for San Augustine County

San Augustine County, Texas

USDA SSURGO / PHZM

Data Story

About Lawn Care in San Augustine County, Texas

Tough Growing Conditions in San Augustine

San Augustine County presents a significant challenge with a lawn difficulty score of 28.1, falling below the state average of 31.7. Residents in Zone 9a must contend with high heat and a climate that is much more demanding than the national average. Success here requires a specialized approach to lawn care and species selection.

Intense Heat and High Humidity Balance

The county experiences 96 extreme heat days annually, which is slightly less than the state average of 105 but still very taxing for grass. Thankfully, 53.9 inches of annual precipitation provides more moisture than the state average of 31.9 inches. This creates a humid environment where warm-season grasses can grow aggressively during the long summer.

Prepare for Local Soil Variations

Specific data on soil pH and clay content is limited for this county, but East Texas regions often feature heavy clays or sandy loams. Conduct a home soil test to determine if your lawn needs lime to balance acidity or organic matter to improve drainage. Proper soil preparation is the only way to ensure your grass survives the 96 days of extreme heat.

A Year of Severe Drought Stress

Current conditions show that 100% of the county is in severe drought, part of a 19-week trend of dry weather over the past year. Even with high annual rain totals, these concentrated dry periods can be devastating to shallow-rooted turf. Prioritize water conservation by only irrigating in the early morning to minimize evaporation.

Warm-Season Grass for Zone 9a

Bermuda and Centipede grass are ideal for the 9a climate because they handle the 6,121 growing degree days with ease. Wait until after the last spring frost on March 18 to seed your lawn to ensure the soil is sufficiently warm. Starting in late March gives your grass a head start before the extreme heat of July arrives.

Lawn Difficulty Score

26/100
Easy
Rainfall18/100
Soil Quality0/100
Temperature48/100
Growing Season40/100
Drought37/100

Soil Summary

pH

N/A

Texture

N/A

Drainage

N/A

Organic Matter

N/A

View full soil details

Top Grass Fit for San Augustine County

Warm-season grasses are the general fit here

County soil and zone data are incomplete, so we show a category recommendation rather than a precise cultivar score for San Augustine County.

Why we ruled these out

  • Outsidepride Midnight Kentucky Bluegrass SeedUSDA zone 9a is above Outsidepride Midnight Kentucky Bluegrass Seed's effective range (2–8); not recommended for this county.

See our fit-score methodology for how survivability is determined.

Recommended Grasses

Warm-SeasonTransition Zone

Bermudagrass

Cynodon dactylon

Drought: 5/5Shade: 1/5
Suitability70%
View Seeds
Warm-SeasonTransition Zone

Zoysiagrass

Zoysia japonica

Drought: 4/5Shade: 3/5
Suitability70%
View Seeds
Warm-Season

St. Augustinegrass

Stenotaphrum secundatum

Drought: 2/5Shade: 4/5
Suitability70%
View Seeds
Warm-Season

Bahiagrass

Paspalum notatum

Drought: 4/5Shade: 2/5
Suitability70%
View Seeds

Best Grass Seed for San Augustine County

Zone 9aWarm-season grasses thrive here.

Find Seeds for Zone 9a

Climate Snapshot

Annual Precip

53.9"

Growing Degree Days

6,120.6

Base 50F

Last Spring Frost

03/18

First Fall Frost

11/13

Days Above 95F

96

Hardiness Zone

9a

Seeding Calendar — Zone 9A

J
F
M
A
M
J
J
A
S
O
N
D
Warm Seed (Best)
Warm Seed (OK)
Warm Seed (Best)
Warm Seed (OK)
Optimal (cool)
Acceptable (cool)
Optimal (warm)
Acceptable (warm)

Seasonal Lawn Care Checklist

Spring

  • Apply pre-emergent herbicide when soil reaches 55F
  • Begin mowing when grass reaches 3 inches
  • Start irrigation if rainfall is below 1 inch/week
  • Soil test every 2-3 years — adjust lime or sulfur as needed

Summer

  • Raise mowing height to reduce heat stress
  • Water deeply 1-2 times per week (1 inch total)
  • Avoid fertilizing cool-season grasses in peak heat
  • Scout for grubs and treat if >10 per sq ft

Fall

  • Overseed warm-season lawns if thinning
  • Apply fall fertilizer (highest N application for cool-season)
  • Continue mowing until growth stops
  • Rake or mulch leaves to prevent smothering

Winter

  • Apply pre-emergent for winter weeds
  • Service mower and sharpen blades
  • Plan spring soil amendments based on fall test
  • Overseed with ryegrass for winter color

Watering Deficit Calculator

50020,000 sq ft

Monthly Deficit

0.0"

inches of water

Monthly Water

0

gallons

Estimated Monthly Cost

$0.00

at $0.008/gallon average

Estimates based on 54" annual precipitation and estimated evapotranspiration. Actual costs vary by local water rates.

Common Lawn Problems in San Augustine County

Excess Moisture & Fungal Disease

High annual rainfall (54 inches) increases risk of fungal diseases like brown patch and dollar spot. Ensure good drainage and avoid overwatering.

Learn more about regional lawn challenges at The Lawn Report.

Lawn Care Advisory: San Augustine County

Lawn Verdict

San Augustine County is in USDA hardiness zone 9a, a warm zone well-suited to heat-tolerant grasses. with winter lows reaching around 20.0°F. and 6,120.6 growing degree days annually, supporting vigorous warm-season lawns. High annual precipitation (53.9 inches) supports lush growth but increases disease pressure.

Seasonal Breakdown

Wait until after March 18 to seed or overseed; soil temperatures should consistently reach 50-55°F. Summers are warm (July averages 82.0°F); monitor for heat stress and water when soil is dry 2-3 inches down. With 95.6 days above 90°F annually, warm-season grasses recover faster from summer stress than cool-season types. Aerate and overseed cool-season lawns by early fall, well before November 13; this is the best renovation window. Mild winters (January averages 47.4°F) allow year-round mowing for warm-season lawns and minimal dormancy.

Watering Guidance

San Augustine County receives abundant rainfall (53.9 inches annually), so lawns rarely need supplemental irrigation. Currently, 100.0% of the county is in severe drought according to the US Drought Monitor. Mandatory watering restrictions may be in effect; follow local guidelines and prioritize tree and shrub watering over turf. Standard warm-season watering of 1 inch per week is usually adequate during summer. High heat accumulation means warm-season grasses use water aggressively — monitor soil moisture regularly.

Regional Context

San Augustine County is close to the Texas average temperature, it is significantly wetter than the state average (22.0 inches more), USDA zone 9a helps guide grass selection compared to neighboring counties.

Want detailed soil composition, drainage classes, and soil series data? View soil details on SoilByCounty.com

Frequently Asked Questions

What USDA hardiness zone is San Augustine County in?
San Augustine County is located in USDA hardiness zone 9a, based on the 2023 USDA Plant Hardiness Zone Map. This zone helps determine which grass species are most likely to thrive in the county's climate.
What is the best grass for San Augustine County?
Bermudagrass is the top recommendation for San Augustine County, with a match score of 70/100. It grows best in zones 7a–10b and requires 20–30 inches of water annually.
How much rainfall does San Augustine County get?
San Augustine County receives an average of 53.9 inches of precipitation per year, based on NOAA 30-year climate normals. This abundant rainfall supports a wide range of grass species with minimal supplemental irrigation.

Data sourced from USDA SSURGO, NOAA Climate Normals (1991-2020), USDA Plant Hardiness Zone Map, and US Drought Monitor. Lawn difficulty scores and grass recommendations are estimates for informational purposes only.

By Evan Brooks, Data EditorUpdated Reviewed by Evan Brooks, Data Editor