When to plant Leeks in St. Clair County County,
Leeks planted in St. Clair County County between March 25 and April 15 matures in 150 days — well before the October 26 first frost. A second sowing from August 17 to August 31 extends the harvest into fall.
When to Plant Leeks in St. Clair County, MO
Leeks are a mild, sweet allium that produces long white shanks. They are more refined than onions and are a key ingredient in soups, stews, and gratins.
St. Clair County, Missouri is in USDA Zone 6b. The average last spring frost is April 8 and the first fall frost is October 26, giving you a growing season of approximately 201 days.
At an elevation of 699 feet, St. Clair County receives approximately 41.1 inches of rainfall annually with predominantly silt loam soil. Summer highs average 90°F, providing good warmth for Leeks during the growing season.
St. Clair County Soil Profile
Soil Type
Silt Loam
Soil pH
5.5-6.7
Drainage
Well Drained
Monthly Watering Guide for Leeks
Leeks needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.
| Month | Leeks Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 1.7" | 0" | ❄️ Dormant |
| Feb | — | 1.5" | 0" | ❄️ Dormant |
| Mar | — | 2.4" | 0" | ❄️ Dormant |
| Apr | 4.3" | 4.3" | 0" | ✅ Rainfall sufficient |
| May | 4.3" | 5.2" | 0" | ✅ Rainfall sufficient |
| Jun | 4.3" | 4.8" | 0" | ✅ Rainfall sufficient |
| Jul | 4.3" | 4.8" | 0" | ✅ Rainfall sufficient |
| Aug | 4.3" | 4.2" | 0.1" | 💧 Light watering |
| Sep | 4.3" | 3.9" | 0.4" | 💧 Light watering |
| Oct | 4.3" | 3.1" | 1.2" | 💧 Light watering |
| Nov | — | 2.9" | 0" | ❄️ Dormant |
| Dec | — | 2.3" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Oct in St. Clair County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Leeks Planting Timeline — St. Clair County, MO
Leeks Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | March 4 | Mar 4 – Mar 18 |
| Transplant Outdoors | April 8 | Apr 8 – Apr 22 |
| Direct Sow | March 25 | Mar 25 – Apr 15 |
| Harvest | July 8 | Jul 8 – Sep 23 |
| Fall Sowing | August 17 | Aug 17 – Aug 31 |
Plant 1" deep · 15" apart · Rows 24" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | Start Indoors Direct Sow |
| April | Transplant Outdoors Direct Sow |
| May | — |
| June | — |
| July | Harvest |
| August | Fall Sowing Harvest |
| September | Harvest |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
Moderate — regular watering
📅 Days to Maturity
90–150 days
🧪 Soil pH
Needs 6–7 · Your soil: N/A
🗺️ USDA Zone
Zone 6b
📆 Growing Season
201 days in St. Clair County
Growing Tips for St. Clair County
Start seeds indoors 10-12 weeks before last frost. Transplant into trenches and hill soil around stems as they grow to increase the white portion. Harvest as needed.
Companion Planting
Good Companions
Avoid Planting Near
Check more plant combinations with our Companion Planting Checker →
Leeks in Other Locations
Frequently Asked Questions
When should I plant Leeks in St. Clair County, MO?
St. Clair County is in Zone 6b with an average last frost of April 8. Plan your Leeks planting based on this frost date — see the calendar above for exact timing.
What planting zone is St. Clair County, MO?
St. Clair County, Missouri is in USDA Hardiness Zone 6b. The average last spring frost is April 8 and first fall frost is October 26.
When should I plant Leeks in St. Clair County County, ?
In St. Clair County County, , plant Leeks after the last frost (around April 8) and before the first frost (around October 26). Best results when soil holds above 50°F.
What growing zone is St. Clair County County, for Leeks?
St. Clair County County sits in USDA Zone 6b. Leeks grows reliably in zones 3a through 10b, so it's a good fit here.
Can Leeks grow in St. Clair County County's climate?
Yes — Leeks grows well in St. Clair County County's temperate climate. St. Clair County County averages a 201-day frost-free season, with last frost around April 8 and first frost around October 26.
Your St. Clair County Garden Planner — Free
A 22-page printable planner built for St. Clair County (Zone 6b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.