When to plant Mint in LaSalle County, IL
Plant Mint in LaSalle County during the brief April 29–May 13 window. With 175 frost-free days, fall plantings can't mature before October 14.
When to Plant Mint in LaSalle County, IL
Mint is a vigorous perennial herb with refreshing, aromatic leaves used in teas, cocktails, and cooking. It spreads aggressively by underground runners.
LaSalle County, Illinois is in USDA Zone 5b. The average last spring frost is April 22 and the first fall frost is October 14, giving you a growing season of approximately 175 days.
At an elevation of 523 feet, LaSalle County receives approximately 39.7 inches of rainfall annually with predominantly silt loam soil. Summer highs average 84°F, so choose short-season varieties of Mint to ensure they mature before fall.
LaSalle County Soil Profile
Soil Type
Silt Loam
Soil pH
5.7-6.9
Drainage
Well Drained
Monthly Watering Guide for Mint
Mint needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.
| Month | Mint Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 1.5" | 0" | ❄️ Dormant |
| Feb | — | 2" | 0" | ❄️ Dormant |
| Mar | — | 2.5" | 0" | ❄️ Dormant |
| Apr | 4.3" | 4.2" | 0.1" | 💧 Light watering |
| May | 4.3" | 4.5" | 0" | ✅ Rainfall sufficient |
| Jun | 4.3" | 4.9" | 0" | ✅ Rainfall sufficient |
| Jul | 4.3" | 4.2" | 0.1" | 💧 Light watering |
| Aug | 4.3" | 3.7" | 0.6" | 💧 Light watering |
| Sep | 4.3" | 3.4" | 0.9" | 💧 Light watering |
| Oct | 4.3" | 3.7" | 0.6" | 💧 Light watering |
| Nov | — | 2.7" | 0" | ❄️ Dormant |
| Dec | — | 2.4" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Oct in LaSalle County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Mint Planting Timeline — LaSalle County, IL
Mint Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Transplant Outdoors | April 29 | Apr 29 – May 13 |
| Harvest | July 1 | Jul 1 – Sep 9 |
Plant 0.5" deep · 8" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | — |
| April | Transplant Outdoors |
| May | Transplant Outdoors |
| June | — |
| July | Harvest |
| August | Harvest |
| September | Harvest |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Partial Shade (3-6 hours)
💧 Water
High — keep soil consistently moist
📅 Days to Maturity
60–90 days
🧪 Soil pH
Needs 6–7 · Your soil: N/A
🗺️ USDA Zone
Zone 5b
📆 Growing Season
175 days in LaSalle County
Growing Tips for LaSalle County
Always grow mint in containers or with underground barriers to control spreading. Harvest regularly to keep plants compact. Cut plants back in late summer for a fresh fall flush.
Companion Planting
Good Companions
Avoid Planting Near
Check more plant combinations with our Companion Planting Checker →
Mint in Other Locations
Frequently Asked Questions
When should I plant Mint in LaSalle County, IL?
LaSalle County is in Zone 5b with an average last frost of April 22. Plan your Mint planting based on this frost date — see the calendar above for exact timing.
What planting zone is LaSalle County, IL?
LaSalle County, Illinois is in USDA Hardiness Zone 5b. The average last spring frost is April 22 and first fall frost is October 14.
When should I plant Mint in LaSalle County, IL?
In LaSalle County, IL, plant Mint after the last frost (around April 22) and before the first frost (around October 14). Best results when soil holds above 50°F.
What growing zone is LaSalle County, IL for Mint?
LaSalle County sits in USDA Zone 5b. Mint grows reliably in zones 3a through 10b, so it's a good fit here.
Can Mint grow in LaSalle County's climate?
Yes — Mint grows well in LaSalle County's temperate climate. LaSalle County averages a 175-day frost-free season, with last frost around April 22 and first frost around October 14.
Your LaSalle County Garden Planner — Free
A 22-page printable planner built for LaSalle County (Zone 5b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.