Lawn Care Guide for Sully County
Sully County, South Dakota
Data Story
About Lawn Care in Sully County, South Dakota
Moderate Maintenance Needs in Sully County
Sully County sits slightly above the national median with a lawn difficulty score of 55.3. This Hardiness Zone 4b region is also more favorable for turf than the South Dakota state average.
Balancing Water and Summer Growth
Annual precipitation averages 21.1 inches, requiring supplemental watering to meet the needs of a standard lawn. Growers navigate 30 extreme heat days and 2,802 growing degree days, which accelerates mowing frequency in early summer.
Nearly Perfect Soil pH Levels
At 6.92, the soil pH is almost perfectly centered in the ideal range for grass health. The soil contains 27.6% clay, providing decent moisture retention while 22.0% sand helps with structural stability.
Seventeen Weeks of Recent Drought
The county endured 17 weeks of drought over the past year, though current data shows 0% of the area is currently in a drought stage. To prepare for future dry spells, homeowners should maintain a taller grass height to shade the soil.
Focus on Fall Recovery
Target the period between May 8th and October 2nd for active growth. Fine fescue or Kentucky Bluegrass are excellent picks for this zone, especially when seeded in the late summer for optimal root establishment.
Lawn Difficulty Score
Recommended Grasses
Blue Grama
Bouteloua gracilis
Tall Fescue
Festuca arundinacea
Climate Snapshot
Annual Precip
21.1"
Growing Degree Days
2,801.6
Base 50F
Last Spring Frost
05/08
First Fall Frost
10/02
Days Above 95F
30
Hardiness Zone
4b
Seeding Calendar — Zone 4B
Seasonal Lawn Care Checklist
Spring
- Apply pre-emergent herbicide when soil reaches 55F
- Overseed bare spots once frost risk passes
- Start irrigation if rainfall is below 1 inch/week
- Soil test every 2-3 years — adjust lime or sulfur as needed
Summer
- Mow at recommended height weekly
- 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
- Core aerate compacted areas
- Apply fall fertilizer (highest N application for cool-season)
- Continue mowing until growth stops
- Rake or mulch leaves to prevent smothering
Winter
- Avoid walking on frozen turf
- Service mower and sharpen blades
- Plan spring soil amendments based on fall test
- Keep lawn clear of debris
Watering Deficit Calculator
Monthly Deficit
2.1"
inches of water
Monthly Water
6,482
gallons
Estimated Monthly Cost
$51.85
at $0.008/gallon average
Estimates based on 21" annual precipitation and estimated evapotranspiration. Actual costs vary by local water rates.
Common Lawn Problems in Sully County
Drought Stress
With only 21 inches of annual rainfall, lawns in Sully County face significant drought stress. Consider drought-tolerant grass species and deep, infrequent watering.
Learn more about regional lawn challenges at The Lawn Report.
Want detailed soil composition, drainage classes, and soil series data? View soil details on SoilByCounty.com
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.
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