LawnByCounty

Lawn Care Guide for Marshall County

Marshall County, Illinois

USDA SSURGO / PHZM

Data Story

About Lawn Care in Marshall County, Illinois

Favorable Lawn Conditions in Zone 5b

Marshall County boasts a 73.7 lawn difficulty score, outperforming both the state average and the national median of 50.0. This score indicates that maintaining a lush green space in Zone 5b is easier here than in many other Illinois regions.

Steady Moisture and Moderate Growing Days

Annual precipitation of 37.9 inches is slightly below the state average but remains within the healthy 30-50 inch window. The climate includes 29 days above 90°F, requiring strategic irrigation to keep grass from entering summer dormancy.

Silt Loam Provides an Excellent Base

Silt loam soil with a 6.58 pH provides an excellent, nutrient-rich foundation for most turfgrass species. Because the soil is classified as somewhat poorly drained, homeowners should focus on aeration to prevent standing water.

100% Severe Drought Coverage

The entire county currently faces severe drought conditions, following 27 weeks of dry spells over the past year. Lawns need deep-root watering early in the morning to maximize absorption and mitigate the current high stress levels.

Kentucky Bluegrass Thrives Here

Wait until the final spring frost on April 20th before beginning your lawn projects. Kentucky bluegrass and fine fescue thrive in these conditions, provided you establish them before the October 17th fall frost.

Lawn Difficulty Score

22/100
Easy
Rainfall0/100
Soil Quality25/100
Temperature14/100
Growing Season40/100
Drought52/100

Soil Summary

pH

6.6

Texture

Silt loam

Drainage

Somewhat poorly drained

Organic Matter

2.7%

View full soil details

Top Grass Fit for Marshall County

100/ 100

Excellent match

Outsidepride Midnight Kentucky Bluegrass Seed

Outsidepride

Top cultivar score: 100/100

USDA Zone Match100

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

Soil pH Fit100

Soil pH 6.57881147827803 vs Kentucky Bluegrass's 6–7 window.

Moisture Fit100

Precipitation 37.870000000000005" + soil AWC vs Kentucky Bluegrass's 30–40" need.

Establishment Window100

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

Let's be direct: Outsidepride Midnight Kentucky Bluegrass is one of the best pure KBG seeds you can buy online, and it's not particularly close. Midnight is a specific cultivar — not a generic "Kentucky bluegrass blend" — and that distinction matters enormously.
From The Lawn Report editorial review • rated 4.7/5
Shop Outsidepride Midnight Kentucky Bluegrass Seed

In Marshall County, USDA zone 5b, soil pH 6.6, silt loam, Outsidepride Midnight Kentucky Bluegrass Seed 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 5b 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 Marshall County

Zone 5bCool-season grasses thrive here.

Find Seeds for Zone 5b

Climate Snapshot

Annual Precip

37.9"

Growing Degree Days

3,651.8

Base 50F

Last Spring Frost

04/20

First Fall Frost

10/17

Days Above 95F

29

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

0.7"

inches of water

Monthly Water

2,266

gallons

Estimated Monthly Cost

$18.13

at $0.008/gallon average

Estimates based on 38" annual precipitation and estimated evapotranspiration. Actual costs vary by local water rates.

Common Lawn Problems in Marshall County

Persistent Drought Conditions

Marshall County experienced drought conditions for 27 of the past 52 weeks. Prioritize water-efficient grasses and consider reducing lawn area.

Learn more about regional lawn challenges at The Lawn Report.

Lawn Care Advisory: Marshall County

Lawn Verdict

Marshall County sits in USDA hardiness zone 5b, a transitional zone where cool-season grasses dominate but some warm-season varieties can survive. with winter lows reaching around -15.0°F. and 3,651.8 growing degree days, sufficient for most common turfgrasses. Moderate rainfall (37.9 inches) generally supports healthy lawns with minimal supplemental watering.

Seasonal Breakdown

Wait until after April 20 to seed or overseed; soil temperatures should consistently reach 50-55°F. Cool summers (July averages 76.0°F) reduce heat stress — maintain regular mowing and moderate watering. Aerate and overseed cool-season lawns by early fall, well before October 17; this is the best renovation window. Cool winters (January averages 25.9°F) mean slow or dormant growth; keep debris off the lawn.

Watering Guidance

With 37.9 inches of annual rainfall, established lawns typically need watering only during extended dry spells. Currently, 100.0% of the county is in severe drought according to the US Drought Monitor. Mandatory watering restrictions may be in effect; follow local guidelines and prioritize tree and shrub watering over turf. Standard warm-season watering of 1 inch per week is usually adequate during summer.

Regional Context

Marshall County is close to the Illinois average temperature, it is somewhat drier than the state average, USDA zone 5b 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 Marshall County in?
Marshall County is located in USDA hardiness zone 5b, 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 Marshall County?
Kentucky Bluegrass is the top recommendation for Marshall 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 Marshall County get?
Marshall County receives an average of 37.9 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 Marshall County?
The average soil pH in Marshall County is 6.6, 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