When to Plant Lentils in St. Louis County, MO
Your April game plan for St. Louis County, Missouri
Welcome to April in Zone 6a. These are the moves that will have the biggest impact on your growing season.
-
Plant out lentils
Frost risk is low now in St. Louis County, Missouri. If you've been covering beds overnight, you can stop.
Coming up in May — start thinking about
- Starting indoors: lentils
Lentils are an ancient pulse crop producing small, lens-shaped seeds packed with protein and iron. They grow on short, bushy plants and are surprisingly easy to cultivate.
St. Louis County, Missouri is in USDA Zone 6a. The average last spring frost is April 13 and the first fall frost is October 24, giving you a growing season of approximately 194 days.
At an elevation of 895 feet, St. Louis County receives approximately 40.1 inches of rainfall annually with predominantly silt loam soil. Summer highs average 86°F, providing good warmth for Lentils during the growing season.
St. Louis County Soil Profile
Soil Type
Silt Loam
Soil pH
5.4-6.6
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.
Soil Compatibility in St. Louis County
How your county's soil matches Lentils's growing requirements.
Soil pH
Your soil pH (5.4–6.6) overlaps with Lentils's range (6.0–8.0), though not a perfect match.
Soil Texture
The silt loam soil in St. Louis County is excellent for Lentils — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is moderate (3.0%). Annual compost additions will help Lentils.
How to Plant Lentils
Fall planting: Sow 10 weeks before your first frost date for a fall harvest.
Succession Planting Lentils
Sow every 9.1 weeks. Last sowing by Jul 06 to harvest before frost.
For a dedicated fall crop, sow by Aug 15.
Plant Water Budget
Monthly Watering Guide for Lentils
Lentils needs approximately 0.6 inches of water per week (2.6" per month). Here's how your county's rainfall compares month by month.
| Month | Lentils Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 1.6" | 0" | ❄️ Dormant |
| Feb | — | 1.8" | 0" | ❄️ Dormant |
| Mar | — | 2.8" | 0" | ❄️ Dormant |
| Apr | 2.6" | 3.7" | 0" | ✅ Rainfall sufficient |
| May | 2.6" | 5.2" | 0" | ✅ Rainfall sufficient |
| Jun | 2.6" | 4.5" | 0" | ✅ Rainfall sufficient |
| Jul | 2.6" | 4.7" | 0" | ✅ Rainfall sufficient |
| Aug | 2.6" | 4.6" | 0" | ✅ Rainfall sufficient |
| Sep | 2.6" | 3.4" | 0" | ✅ Rainfall sufficient |
| Oct | 2.6" | 3.5" | 0" | ✅ Rainfall sufficient |
| Nov | — | 2.5" | 0" | ❄️ Dormant |
| Dec | — | 1.9" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Oct in St. Louis County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Lentils Heat Requirements (GDD)
What are Growing Degree Days (GDD)?
Growing Degree Days measure the total warmth your plants receive during the growing season. Think of it as a "heat bank" — every day above 50°F deposits warmth that helps your plants grow.
Each plant needs a certain amount of accumulated heat to mature. If your county provides more GDD than the plant needs, it's a great fit. If it's close, you may want to choose faster-maturing varieties or start seeds indoors to get a head start.
Lentils Planting Timeline — St. Louis County, MO
Lentils Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | March 9 | Mar 9 – Mar 23 |
| Transplant Outdoors | April 13 | Apr 13 – Apr 27 |
| Direct Sow | March 30 | Mar 30 – Apr 20 |
| Harvest | July 6 | Jul 6 – Aug 17 |
| Fall Sowing | August 15 | Aug 15 – Aug 29 |
Plant 0.5" deep · 6" apart · Rows 12" 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 | — |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
0.6"/week · Natural rainfall sufficient
📅 Days to Maturity
80–110 days
🧪 Soil pH
Needs 6–8 · Your soil: acceptable
🗺️ USDA Zone
Zone 6a
📆 Growing Season
194 days in St. Louis County
Growing Tips for Lentils in St. Louis County
Direct sow Lentils outdoors after April 13 in St. Louis County when soil has warmed and frost danger has passed.
Common pests for Lentils in this region include bean beetles and aphids. Use row covers early in the season and inspect plants weekly.
General growing tips
Direct sow in early spring as lentils tolerate frost. Provide short supports as plants tend to lodge. Harvest when lower pods turn brown. Pull entire plants and dry in bundles.
Companion Planting
Good Companions
Avoid Planting Near
Check more plant combinations with our Companion Planting Checker →
Lentils in Other Locations
Frequently Asked Questions
When should I plant Lentils in St. Louis County, MO?
St. Louis County is in Zone 6a with an average last frost of April 13. Plan your Lentils planting based on this frost date — see the calendar above for exact timing.
What planting zone is St. Louis County, MO?
St. Louis County, Missouri is in USDA Hardiness Zone 6a. The average last spring frost is April 13 and first fall frost is October 24.
Your St. Louis County Garden Planner — Free
A 24-page printable planner built for St. Louis County (Zone 6a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.