When to Plant Lettuce in Marshall County, IL
Lettuce is a fast-growing cool-season green available in leaf, romaine, butterhead, and crisphead types. It is the foundation of salads and one of the easiest crops to grow.
Marshall County, Illinois is in USDA Zone 5a. The average last spring frost is April 21 and the first fall frost is October 13, giving you a growing season of approximately 175 days.
At an elevation of 1,177 feet, Marshall County receives approximately 30.4 inches of rainfall annually with predominantly silt loam soil. Summer highs average 84°F, so choose short-season varieties of Lettuce to ensure they mature before fall.
Marshall County Soil Profile
Soil Type
Silt Loam
Soil pH
6-6.8
Drainage
Well Drained
Plant Planting Risk Windows
Percentages indicate frost risk at transplant. The 70% safe window means there is a 30% chance of frost after transplant — suitable for cold-hardy crops or gardeners with frost protection. The 90% safe window is best for tender plants.
Plant Water Budget
Water stress score is 6/10 — consider drought-tolerant varieties and mulching
Lettuce Planting Timeline — Marshall County, IL
Lettuce Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | March 17 | Mar 17 – Mar 31 |
| Transplant Outdoors | April 21 | Apr 21 – May 5 |
| Direct Sow | April 7 | Apr 7 – Apr 28 |
| Fall Sowing | August 4 | Aug 4 – Aug 18 |
| Harvest | May 26 | May 26 – Aug 4 |
Plant 0.5" deep · 6" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | Start Indoors |
| April | Transplant Outdoors Direct Sow |
| May | Transplant Outdoors Harvest |
| June | Harvest |
| July | Harvest |
| August | Fall Sowing Harvest |
| September | — |
| October | — |
| November | — |
| December | — |
Growing Conditions
Sun
Partial Shade (3-6 hours)
Water
Moderate — regular watering
Days to Maturity
30–60 days
Soil pH
6 – 7
USDA Zone
Zone 5a
Growing Season
175 days
Growing Tips for Marshall County
Sow seeds directly every 2 weeks for continuous harvest. Provide afternoon shade in warm weather to delay bolting. Harvest in the morning for crispest leaves.
Companion Planting
Good Companions
Avoid Planting Near
Level Up Your Garden
Very easy to save. Let a few plants bolt each season.
Lettuce in Other Locations
Frequently Asked Questions
When should I plant Lettuce in Marshall County, IL?
Marshall County is in Zone 5a with an average last frost of April 21. Plan your Lettuce planting based on this frost date — see the calendar above for exact timing.
What planting zone is Marshall County, IL?
Marshall County, Illinois is in USDA Hardiness Zone 5a. The average last spring frost is April 21 and first fall frost is October 13.
Plan Your Garden with Confidence
Get our free Garden Planner — designed to help Marshall County gardeners in Zone 5a organize planting dates, track what's growing, and never miss a planting window.
Get Your Free Garden Planner →Free download. Plan your entire garden season in minutes.