Lawn Care Guide for Treasure County
Treasure County, Montana
USDA SSURGO / PHZMData Story
About Lawn Care in Treasure County, Montana
Treasure County's Above-Average Growing Conditions
With a score of 46.1, Treasure County is one of the easier places in Montana to grow a lawn, beating the state average by nearly 13 points. It sits in hardiness zone 4b, requiring plants that can handle deep winter freezes. Despite the higher score, it still faces the semi-arid challenges typical of the Big Sky state.
High Heat and Moderate Growth
This county experiences 35 days of extreme heat annually, far more than the state average of 22 days. This heat, combined with 2302 growing degree days, means grass grows quickly but requires more water to prevent dormancy. With only 14.9 inches of annual rain, your irrigation system will be the primary source of moisture.
Working with Alkaline Clay Soil
The soil pH is 7.59, trending more alkaline than the ideal 7.0 maximum for most turf. A soil blend of 29.0% clay and 38.8% sand means your lawn can hold onto nutrients well but may suffer from poor drainage if overwatered. Adding sulfur or organic compost can help lower the pH to a more comfortable level for your grass.
Short-Term Dryness and Resilience
The county only saw 2 weeks of drought over the past year, though 100% of the area is currently considered abnormally dry. This recent dry spell suggests a need for vigilance even when long-term conditions seem favorable. Frequent, shallow watering should be avoided in favor of deep soaking to prepare for the high-heat days.
Sowing Success in Treasure County
Kentucky Bluegrass remains a favorite here for its ability to recover from heat stress if watered properly. The planting window begins after the last spring frost on May 26 and extends until the first fall frost on September 29. Early autumn is often the best time to seed here, as the soil remains warm while air temperatures cool.
Lawn Difficulty Score
Top Grass Fit for Treasure County
Strong match
Pennington Smart Seed Sun & Shade
Pennington
Top cultivar score: 74/100
Estimated — county soil data incomplete.
Zone 4b vs Tall Fescue's 3–8 band.
Soil pH 7.58962084512575 vs Tall Fescue's 5.5–6.5 window.
Precipitation 14.91" + soil AWC vs Tall Fescue's 20–30" need.
Growing-degree-days + frost window vs a beginner-difficulty establishment.
Pennington Smart Seed Sun & Shade is the best value in the cool-season grass seed market. Period. You get a quality fescue/KBG blend with genuine drought tolerance coating at a price point significantly below premium options like BBU or Barenbrug RTF.
In Treasure County, USDA zone 4b, soil pH 7.6, Pennington Smart Seed Sun & Shade scores 74/100 — a strong zone match, moderate moisture, and a long enough establishment window.
Why we ruled these out
- Pennington Zenith Zoysia Grass Seed & Mulch — USDA zone 4b is below Pennington Zenith Zoysia Grass Seed & Mulch's effective range (5–10); not recommended for this county.
- Scotts Turf Builder Bermudagrass — USDA zone 4b is below Scotts Turf Builder Bermudagrass's effective range (6–11); not recommended for this county.
See our fit-score methodology for how survivability is determined.
Recommended Grasses
Blue Grama
Bouteloua gracilis
Tall Fescue
Festuca arundinacea
Buffalograss
Bouteloua dactyloides
Climate Snapshot
Annual Precip
14.9"
Growing Degree Days
2,302.2
Base 50F
Last Spring Frost
05/26
First Fall Frost
09/29
Days Above 95F
35
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
2.5"
inches of water
Monthly Water
7,813
gallons
Estimated Monthly Cost
$62.50
at $0.008/gallon average
Estimates based on 15" annual precipitation and estimated evapotranspiration. Actual costs vary by local water rates.
Common Lawn Problems in Treasure County
Drought Stress
With only 15 inches of annual rainfall, lawns in Treasure County face significant drought stress. Consider drought-tolerant grass species and deep, infrequent watering.
Learn more about regional lawn challenges at The Lawn Report.
Lawn Care Advisory: Treasure County
Lawn Verdict
Treasure County is in USDA hardiness zone 4b, one of the coldest zones in the country. with winter lows reaching around -25.0°F. though only 2,302.2 growing degree days favor cool-season varieties like Kentucky bluegrass and fescue. Low rainfall (14.9 inches) means supplemental irrigation is essential during summer months.
Seasonal Breakdown
Wait until after May 26 to seed or overseed; soil temperatures should consistently reach 50-55°F. Cool summers (July averages 71.5°F) reduce heat stress — maintain regular mowing and moderate watering. With 34.65 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 September 29; this is the best renovation window. Cool winters (January averages 22.4°F) mean slow or dormant growth; keep debris off the lawn.
Watering Guidance
Low annual precipitation (14.9 inches) makes irrigation essential for maintaining green turf through summer. Currently, 100.0% of the county is in abnormally dry according to the US Drought Monitor. Cool summers reduce water demand; overwatering is a bigger risk than drought stress.
Regional Context
Treasure County is close to the Montana average temperature, USDA zone 4b 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 Treasure County in?
What is the best grass for Treasure County?
How much rainfall does Treasure County get?
What is the soil pH in Treasure 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 Treasure County