Lawn Care Guide for Sumner County
Sumner County, Tennessee
USDA SSURGO / PHZMThis week in Sumner County · next up in about 5 weeks (Sep 3)
Get ready to seed cool-season grass — the best fall window is about to open.
Data Story
About Lawn Care in Sumner County, Tennessee
Sumner County Lawn Care Overview
With a lawn difficulty score of 53.9, Sumner County is friendlier to grass than the national median of 50.0. This Zone 7b county provides a solid environment for homeowners looking for a lush landscape. You can expect fewer maintenance headaches here than in the more difficult 48.0 state average regions.
Heat and Rain in the Middle State
Sumner receives 54.5 inches of rain annually, slightly exceeding the ideal 50-inch threshold. You will deal with 37 extreme heat days annually, mirroring the state average of 36. These conditions require a careful balance of drainage and summer irrigation to keep grass from wilting.
Managing Well-Drained Clay Loam
The soil pH of 5.71 is slightly acidic but closer to the ideal 6.0-7.0 range than many neighboring counties. This well-drained clay loam contains 22.6% clay, providing good structure for holding essential nutrients. Minimal lime applications can help bridge the gap to a perfect nutrient-ready soil.
Drought Resilience and Water Use
The county experienced only 10 weeks in drought over the last year, though 47.8% of the area is currently abnormally dry. Use mulch-mowing to return clippings to the soil, which helps retain moisture and nutrients. This practice is particularly helpful during the 37 days when temperatures soar above 90°F.
Planting Windows for Sumner Lawns
Warm-season grasses like Zoysia or cool-season Tall Fescue both perform well in this climate. Time your planting between the last spring frost on April 7 and the first fall frost on October 30. Your lawn has a great foundation, so start your seasonal prep this week.
Lawn Difficulty Score
Top Grass Fit for Sumner County
Excellent match
Jonathan Green Black Beauty Ultra
Jonathan Green
Top cultivar score: 100/100
Zone 7b vs Tall Fescue's 3–8 band.
Soil pH 5.71067260605337 vs Tall Fescue's 5.5–6.5 window.
Precipitation 54.54" + soil AWC vs Tall Fescue's 20–30" need.
Growing-degree-days + frost window vs a intermediate-difficulty establishment.
If you spend any time on lawn care forums, Reddit's r/lawncare, or YouTube lawn channels, one name comes up more than any other: Jonathan Green Black Beauty Ultra. It's practically a cult favorite, and the label, cultivar story, and long-running owner reports explain why. The secret is in the genetics.
In Sumner County, USDA zone 7b, soil pH 5.7, clay loam, Jonathan Green Black Beauty Ultra scores 100/100 — a strong zone match, adequate moisture, and a long enough establishment window.
Recommended Grasses
Tall Fescue
Festuca arundinacea
Bermudagrass
Cynodon dactylon
Choosing grass in Sumner County
Your silty soil and transition-zone conditions narrow the field fast. Here's how to think it through for Sumner County — then the specific pick.
- Bermuda vs. Zoysia in the transition zoneThe classic call where warm- and cool-season grasses overlap.
- How grass cultivars get scored (NTEP)The independent trial data behind every species ranking.
- Tall Fescue, explainedTraits, care, and where Tall Fescue wins — the species behind your top match.
Top match for Sumner County: Tall Fescue
See the full breakdownPremium Grass Seeds is a sister site in our network. We may earn a commission from qualifying purchases made through its retailer links — this never affects your price. Guidance here reflects your county’s climate and soil data, not hands-on testing.
Climate Snapshot
Annual Precip
54.5"
Growing Degree Days
4,360.133
Base 50F
Last Spring Frost
04/07
First Fall Frost
10/30
Days Above 95F
37
Hardiness Zone
7b
Seeding Calendar — Sumner County
Personalized to this county’s frost dates — a 206-day growing season. Windows below are computed from local last-spring and first-fall frost normals, so they differ county-to-county even within USDA Zone 7B.
Plan your seeding — Sumner County
Pick a grass and a goal to get a personalized schedule anchored to this county’s frost dates.
- 1Prepare the seedbedAug 20 – Sep 2
Mow low, dethatch or rake, and loosen the top ½ inch of soil so seed makes good contact.
- 2Sow seedSep 3 – Oct 1
Best window to sow Tall Fescue in Sumner County, anchored to your local frost dates.
- 3EstablishOct 2 – Oct 29
Protect young seedlings: mow only after they reach ~3 inches and hold off on weed pre-emergents until established.
Silt retains moisture well — keep the seedbed consistently damp with about ¼ inch once daily, easing off if the surface stays wet to avoid damping-off.
You’re in the transition zone — both cool- and warm-season grasses can work; the schedule above follows the species you selected.
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
- 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
- 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
- Keep lawn clear of debris
Watering Deficit Calculator
Monthly Deficit
0.0"
inches of water
Monthly Water
0
gallons
Estimated Monthly Cost
$0.00
at $0.008/gallon average
Estimates based on 55" annual precipitation and estimated evapotranspiration. Actual costs vary by local water rates.
Common Lawn Problems in Sumner County
Excess Moisture & Fungal Disease
High annual rainfall (55 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: Sumner County
Lawn Verdict
Sumner County falls in USDA hardiness zone 7b, a favorable range for both cool- and warm-season grasses. with winter lows reaching around 5.0°F. and 4,360.133 growing degree days annually, supporting vigorous warm-season lawns. High annual precipitation (54.5 inches) supports lush growth but increases disease pressure.
Seasonal Breakdown
Wait until after April 7 to seed or overseed; soil temperatures should consistently reach 50-55°F. Cool summers (July averages 78.1°F) reduce heat stress — maintain regular mowing and moderate watering. With 37.266666666666666 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 October 30; this is the best renovation window. Cool winters (January averages 36.0°F) mean slow or dormant growth; keep debris off the lawn.
Watering Guidance
Sumner County receives abundant rainfall (54.5 inches annually), so lawns rarely need supplemental irrigation. Currently, 51.0% of the county is in abnormally dry according to the US Drought Monitor. Standard warm-season watering of 1 inch per week is usually adequate during summer.
Regional Context
Sumner County is close to the Tennessee average temperature, USDA zone 7b helps guide grass selection compared to neighboring counties.
Dig deeper into Sumner County
Sumner County is a USDA Zone 7B, silty-soil, transition-zone county. Explore the data that shapes its lawn:
Want detailed soil composition, drainage classes, and soil series data? View soil details on SoilByCounty.com
Frequently Asked Questions
What USDA hardiness zone is Sumner County in?
What is the best grass for Sumner County?
How long is the growing season in Sumner County?
How much rainfall does Sumner County get?
What is the soil pH in Sumner County?
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.
Explore more data for Sumner County