LawnByCounty

Lawn Care Guide for Winnebago County

Winnebago County, Iowa

USDA SSURGO / PHZM

Data Story

About Lawn Care in Winnebago County, Iowa

Northern Iowa’s Cool-Season Advantage

Winnebago County scores an 81.2 for lawn difficulty, benefiting from the cooler temperatures of Hardiness Zone 5a. The environment is considerably easier for lawn care than the national average, though it requires specific northern-adapted grass types.

Minimal Heat Stress and Cool Nights

With a mere 9 extreme heat days per year, your grass is less likely to enter summer dormancy compared to the rest of the state. The 36.5 inches of precipitation aligns perfectly with the state average, keeping the ground adequately hydrated.

Sandy Loam Characteristics

The soil features a high sand content of 34.6% and a healthy 6.54 pH. This combination provides excellent drainage and nutrient availability, though you should keep an eye on moisture levels during prolonged dry spells.

Watch for Abnormally Dry Conditions

Winnebago is currently 100% abnormally dry, following 6 weeks of drought over the past year. Using mulch-mowing techniques can help keep moisture in the soil and protect the roots from drying out too quickly.

Respect the Northern Frost Dates

The last spring frost occurs late on April 30, so wait until May to start your heavy seeding. Focus on cool-season varieties that thrive in the 2601 growing degree days available in this northern Iowa county.

Lawn Difficulty Score

10/100
Easy
Rainfall0/100
Soil Quality0/100
Temperature5/100
Growing Season40/100
Drought12/100

Soil Summary

pH

6.5

Texture

N/A

Drainage

N/A

Organic Matter

8.1%

View full soil details

Top Grass Fit for Winnebago County

100/ 100

Excellent match

Scotts EZ Seed Patch & Repair Sun & Shade

Scotts

Top cultivar score: 100/100

Estimated — county soil data incomplete.

USDA Zone Match100

Zone 5a vs Kentucky Bluegrass's 3–7 band.

Soil pH Fit100

Soil pH 6.54421069208549 vs Kentucky Bluegrass's 6–7 window.

Moisture Fit100

Precipitation 36.54" + soil AWC vs Kentucky Bluegrass's 30–40" need.

Establishment Window100

Growing-degree-days + frost window vs a beginner-difficulty establishment.

EZ Seed is the duct tape of lawn care — it's not the most elegant solution, but it works, and it works every time. The combination of grass seed, mulch (ground wood fiber), and fertilizer in one product solves the three biggest reasons bare spot repairs fail: poor seed-to-soil contact, seeds drying out, and no starter…
From The Lawn Report editorial review • rated 4.0/5
Shop Scotts EZ Seed Patch & Repair Sun & Shade

In Winnebago County, USDA zone 5a, soil pH 6.5, Scotts EZ Seed Patch & Repair Sun & Shade scores 100/100 — a strong zone match, adequate moisture, and a long enough establishment window.

Why we ruled these out

  • Scotts Turf Builder BermudagrassUSDA zone 5a 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

Cool-Season

Kentucky Bluegrass

Poa pratensis

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

Perennial Ryegrass

Lolium perenne

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

Buffalograss

Bouteloua dactyloides

Drought: 5/5Shade: 1/5
Suitability70%
View Seeds
Warm-SeasonTransition Zone

Blue Grama

Bouteloua gracilis

Drought: 5/5Shade: 1/5
Suitability70%
View Seeds

Best Grass Seed for Winnebago County

Zone 5aCool-season grasses thrive here.

Find Seeds for Zone 5a

Climate Snapshot

Annual Precip

36.5"

Growing Degree Days

2,600.9

Base 50F

Last Spring Frost

04/30

First Fall Frost

10/07

Days Above 95F

9

Hardiness Zone

5a

Seeding Calendar — Zone 5A

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

0.7"

inches of water

Monthly Water

2,193

gallons

Estimated Monthly Cost

$17.55

at $0.008/gallon average

Estimates based on 37" annual precipitation and estimated evapotranspiration. Actual costs vary by local water rates.

Lawn Care Advisory: Winnebago County

Lawn Verdict

Winnebago County sits in USDA hardiness zone 5a, a transitional zone where cool-season grasses dominate but some warm-season varieties can survive. with winter lows reaching around -20.0°F. and 2,600.9 growing degree days, sufficient for most common turfgrasses. Moderate rainfall (36.5 inches) generally supports healthy lawns with minimal supplemental watering.

Seasonal Breakdown

Wait until after April 30 to seed or overseed; soil temperatures should consistently reach 50-55°F. Cool summers (July averages 71.4°F) reduce heat stress — maintain regular mowing and moderate watering. Aerate and overseed cool-season lawns by early fall, well before October 7; this is the best renovation window. Winters are harsh (January averages 14.1°F); avoid foot traffic on frozen turf and plan snow mold prevention.

Watering Guidance

With 36.5 inches of annual rainfall, established lawns typically need watering only during extended dry spells. Currently, 100.0% of the county is in moderate drought according to the US Drought Monitor. Consider reducing irrigation frequency and allowing cool-season lawns to go semi-dormant during peak heat. Cool summers reduce water demand; overwatering is a bigger risk than drought stress.

Regional Context

Winnebago County is 3.1°F cooler than the Iowa average, USDA zone 5a 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 Winnebago County in?
Winnebago County is located in USDA hardiness zone 5a, based on the 2023 USDA Plant Hardiness Zone Map. This zone helps determine which grass species are most likely to thrive in the county's climate.
What is the best grass for Winnebago County?
Kentucky Bluegrass is the top recommendation for Winnebago County, with a match score of 70/100. It grows best in zones 3a–7a and requires 30–40 inches of water annually.
How much rainfall does Winnebago County get?
Winnebago County receives an average of 36.5 inches of precipitation per year, based on NOAA 30-year climate normals. This provides adequate moisture for most lawn grasses with occasional supplemental watering during dry spells.
What is the soil pH in Winnebago County?
The average soil pH in Winnebago County is 6.5, based on USDA SSURGO data. This near-neutral pH supports most common lawn grasses with minimal soil amendment.

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.

By Evan Brooks, Data EditorUpdated Reviewed by Evan Brooks, Data Editor