Lawn Care Guide for Jefferson County

Jefferson County, Iowa

Data Story

About Lawn Care in Jefferson County, Iowa

Jefferson County: A Reliable Growing Environment

Jefferson County holds a lawn difficulty score of 75.9, which is very close to the Iowa average of 77.2. It remains far easier to manage a lawn here than in the average American county. The Zone 5b hardiness rating allows for a versatile selection of cool-season turf varieties.

Managing High Heat and Higher Rainfall

Homeowners must manage 24 extreme heat days per year, which is significantly more than the state average of 16. Fortunately, 38.4 inches of annual precipitation helps offset the stress caused by the 3,143 growing degree days. Frequent mowing is necessary in the spring to keep up with rapid growth.

Slightly Acidic Soils and Clay Density

A soil pH of 6.18 provides a healthy environment for nutrient uptake, though it is on the lower end of the ideal range. The soil contains 25.2% clay and only 18.0% sand, meaning it holds water well but can be prone to compaction. Core aeration is a recommended annual task to improve root oxygen levels.

Moderate Drought Risk in Southeast Iowa

The county experienced 15 weeks of drought in the last year, and currently, 100% of the land is considered abnormally dry. While heat days are high, the lack of severe D2+ drought currently simplifies maintenance. Focus on consistent hydration during the hot July and August months to prevent summer dormancy.

Heat-Tolerant Grasses Perform Best

Given the 24 heat days, a Turf-Type Tall Fescue blend is ideal for its deep roots and heat resistance. Seeding should occur after the last frost on April 27 or before the first frost on October 12. These windows ensure the grass establishes before the temperature extremes of summer or winter.

Lawn Difficulty Score

13/100
Easy
Rainfall0/100
Soil Quality0/100
Temperature12/100
Growing Season40/100
Drought29/100

Soil Summary

pH

6.2

Texture

N/A

Drainage

N/A

Organic Matter

2.6%

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

38.4"

Growing Degree Days

3,143.3

Base 50F

Last Spring Frost

04/27

First Fall Frost

10/12

Days Above 95F

24

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

1,924

gallons

Estimated Monthly Cost

$15.39

at $0.008/gallon average

Estimates based on 38" 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.