When to plant Lemon Thyme in LaSalle County, IL
In LaSalle County, Lemon Thyme is a single-season spring crop — there's no second fall window. Plant April 29–May 13 for an 70–90-day harvest, finishing well before the October 14 first frost.
When to Plant Lemon Thyme in LaSalle County, IL
Lemon thyme is a low-growing perennial herb with tiny, citrus-scented leaves. It combines the savory quality of thyme with a bright lemon flavor, excellent with fish and poultry.
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 Lemon Thyme 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 Lemon Thyme
Lemon Thyme needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.
| Month | Lemon Thyme 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.
Lemon Thyme Planting Timeline — LaSalle County, IL
Lemon Thyme Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Transplant Outdoors | April 29 | Apr 29 – May 13 |
| Harvest | July 8 | Jul 8 – 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
Full Sun (6-8+ hours)
💧 Water
Low — drought tolerant
📅 Days to Maturity
70–90 days
🧪 Soil pH
Needs 6–8 · Your soil: N/A
🗺️ USDA Zone
Zone 5b
📆 Growing Season
175 days in LaSalle County
Growing Tips for LaSalle County
Start from cuttings or divisions. Plant in well-drained soil. Trim back after flowering. Use as a fragrant ground cover or edging plant along garden paths.
Companion Planting
Good Companions
Check more plant combinations with our Companion Planting Checker →
Lemon Thyme in Other Locations
Frequently Asked Questions
When should I plant Lemon Thyme in LaSalle County, IL?
LaSalle County is in Zone 5b with an average last frost of April 22. Plan your Lemon Thyme 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 Lemon Thyme in LaSalle County, IL?
In LaSalle County, IL, plant Lemon Thyme 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 Lemon Thyme?
LaSalle County sits in USDA Zone 5b. Lemon Thyme grows reliably in zones 5a through 9b, so it's a good fit here.
Can Lemon Thyme grow in LaSalle County's climate?
Yes — Lemon Thyme 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.