Lawn Care Guide for Decatur County

Decatur County, Iowa

Data Story

About Lawn Care in Decatur County, Iowa

Decatur County Leads in Lawn Ease

With a score of 85.1, Decatur County is one of the easiest places in the nation to maintain a healthy lawn. This score dwarfs the national average of 50.0, suggesting that the 5b hardiness zone here is nearly perfect for residential turf.

High Rainfall Boosts Turf Vitality

Annual precipitation reaches 39.2 inches, providing more natural irrigation than the typical Iowa county. Despite 21 extreme heat days, the 3378 growing degree days support a vigorous and long growing season for cool-season grasses.

Balanced Soil for Healthy Roots

The local soil pH of 6.18 is well-suited for lawn health, sitting comfortably within the 6.0-7.0 target. While detailed drainage data is limited, the 26.9% clay content suggests the soil holds onto nutrients and moisture effectively.

Strong Resilience to Water Stress

Decatur County experienced only 2 weeks of drought in the past year, though the entire county is currently labeled as abnormally dry. Maintaining a taller grass height of 3 to 4 inches can help shade the soil and reduce evaporation during these dry stretches.

Take Advantage of a Long Season

The spring frost usually clears by April 17, offering an early start for seeding or sodding projects. With the first fall frost not expected until October 21, you have a generous window to establish a lush, green lawn.

Lawn Difficulty Score

11/100
Easy
Rainfall0/100
Soil Quality0/100
Temperature11/100
Growing Season40/100
Drought4/100

Soil Summary

pH

6.2

Texture

N/A

Drainage

N/A

Organic Matter

2.7%

View full soil details

Recommended Grasses

Cool-Season

Kentucky Bluegrass

Poa pratensis

Drought: 2/5Shade: 2/5
Suitability70%
View Seeds
Cool-SeasonTransition Zone

Tall Fescue

Festuca arundinacea

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

Perennial Ryegrass

Lolium perenne

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

Fine Fescue

Festuca spp.

Drought: 3/5Shade: 5/5
Suitability70%
View Seeds

Climate Snapshot

Annual Precip

39.2"

Growing Degree Days

3,378.367

Base 50F

Last Spring Frost

04/17

First Fall Frost

10/21

Days Above 95F

21

Hardiness Zone

5b

Seeding Calendar — Zone 5B

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

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

50020,000 sq ft

Monthly Deficit

0.6"

inches of water

Monthly Water

1,869

gallons

Estimated Monthly Cost

$14.96

at $0.008/gallon average

Estimates based on 39" annual precipitation and estimated evapotranspiration. Actual costs vary by local water rates.

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.