Lawn Care Guide for Coos County
Coos County, New Hampshire
Data Story
About Lawn Care in Coos County, New Hampshire
Coos County Surpasses State Lawn Averages
Coos County holds a lawn difficulty score of 50.8, making it slightly easier to manage turf here than the national median. This score is significantly better than the New Hampshire state average of 47.9, showing that northern lawns can thrive despite the Zone 4b winters. While the season is short, the conditions are surprisingly favorable for consistent grass growth.
Cool Summers and a Short Growing Window
This county enjoys 47.9 inches of annual rain and only 2 extreme heat days, which is excellent for preventing grass wilt. However, the growing season is the shortest in the state, with the last frost on May 23 and the first frost on September 29. With only 1,542 growing degree days, mowing will be less frequent than in southern regions.
Preparing Northern Soil for Success
Specific local soil data is currently unavailable, but the region's climate often produces organic-rich but potentially thin soils. Homeowners should focus on aerating in the spring to combat any compaction from heavy snow loads. A soil test will help determine if you need to add nutrients to make the most of the limited growing weeks.
Resilience During Northern Dry Spells
The county has experienced 31 weeks in drought over the past year, with 41.6% of the area currently seeing severe conditions. Fortunately, the lack of extreme heat means lawns lose less water to evaporation than those in southern New Hampshire. Maintaining a higher mowing height during the summer months will help the grass survive these dry periods by protecting the soil surface.
Cold-Hardy Grass for a Short Season
Kentucky Bluegrass is the gold standard for Zone 4b because it handles the deep winter freezes of the North Country exceptionally well. You should aim to seed by early August to ensure the grass is well-established before the September 29 frost date. Despite the short summer, your county's favorable score indicates your lawn will reward your efforts.
Lawn Difficulty Score
Recommended Grasses
Tall Fescue
Festuca arundinacea
Climate Snapshot
Annual Precip
47.9"
Growing Degree Days
1,542.145
Base 50F
Last Spring Frost
05/23
First Fall Frost
09/29
Days Above 95F
2
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
0.0"
inches of water
Monthly Water
0
gallons
Estimated Monthly Cost
$0.00
at $0.008/gallon average
Estimates based on 48" annual precipitation and estimated evapotranspiration. Actual costs vary by local water rates.
Common Lawn Problems in Coos County
Persistent Drought Conditions
Coos County experienced drought conditions for 31 of the past 52 weeks. Prioritize water-efficient grasses and consider reducing lawn area.
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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