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When to Plant Cabbage in St. Louis County, MO

St. Louis County, Missouri Zone 7a May

What to do in May

Here's what deserves your attention in St. Louis County, Missouri this month. Everything below is tailored to Zone 7a and timed around your local frost dates.

Avg. last frost April 13
Avg. first frost October 24
Soil temp (4") 65°F
Watering Low
Pest pressure Low
Daylight 14.1 hrs
  1. Start cabbage under lights

    Your window is short. These crops want several weeks of indoor growth before they go outside.

A few tasks this May that'll pay off in June
  • First harvests: cabbage

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Cabbage is a versatile cool-season crop that forms dense, leafy heads in green, red, or savoy varieties. It is a staple for coleslaw, sauerkraut, and many global cuisines.

St. Louis County, Missouri is in USDA Zone 7a. 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 Cabbage during the growing season.

St. Louis County, MO (Zone 7a) Moderate season
194 days
Last Spring Frost April 13
194 growing days
First Fall Frost October 24
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St. Louis County Soil Profile

Soil Type

Silt Loam

Soil pH

5.4-6.6

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (75 days to spare)
Start indoors: Mar 2 Transplant: Apr 6 🍅 Harvest: Jun 8 – Aug 3
Recommended (50%) ✓ Fits season (75 days to spare)
Start indoors: Mar 9 Transplant: Apr 13 🍅 Harvest: Jun 15 – Aug 10
Safe Start (90%) ✓ Fits season (74 days to spare)
Start indoors: Mar 22 Transplant: Apr 26 🍅 Harvest: Jun 28 – Aug 23

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 Cabbage's growing requirements.

Soil pH

Your soil pH (5.4–6.6) overlaps with Cabbage's range (6.0–7.5), though not a perfect match.

Soil Texture

The silt loam soil in St. Louis County is excellent for Cabbage — good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is moderate (3.0%). Annual compost additions will help Cabbage.

How to Plant Cabbage

1"
Planting Depth
15"
Between Plants
24"
Between Rows

Fall planting: Sow 10 weeks before your first frost date for a fall harvest.

Succession Planting Cabbage

3
successive plantings in your 194-day season

Sow every 6.9 weeks. Last sowing by Jul 16 to harvest before frost.

For a dedicated fall crop, sow by Aug 15.

Plant Water Budget

Plant needs
0.9″/week
Rainfall provides
0.9″/week
You supply
0.0″/week
Watering frequency Only during dry spells
Season total 55 gal / 100 sq ft

Monthly Watering Guide for Cabbage

Cabbage needs approximately 0.9 inches of water per week (3.9" per month). Here's how your county's rainfall compares month by month.

Month Cabbage Needs Rainfall You Supplement Action
Jan 1.6" 0" ❄️ Dormant
Feb 1.8" 0" ❄️ Dormant
Mar 2.8" 0" ❄️ Dormant
Apr 3.9" 3.7" 0.2" 💧 Light watering
May 3.9" 5.2" 0" ✅ Rainfall sufficient
Jun 3.9" 4.5" 0" ✅ Rainfall sufficient
Jul 3.9" 4.7" 0" ✅ Rainfall sufficient
Aug 3.9" 4.6" 0" ✅ Rainfall sufficient
Sep 3.9" 3.4" 0.5" 💧 Light watering
Oct 3.9" 3.5" 0.4" 💧 Light watering
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.

Cabbage 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.

Cabbage needs ~1,160 GDD — county provides 2,813 GDD Excellent fit

Cabbage Planting Timeline — St. Louis County, MO

Cabbage 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 June 15 Jun 15 – Aug 10
Fall Sowing August 15 Aug 15 – Aug 29

Plant 1" deep · 15" apart · Rows 24" apart

Month-by-Month Timeline

MonthActivities
January
February
March Start Indoors Direct Sow
April Transplant Outdoors Direct Sow
May
June Harvest
July Harvest
August Fall Sowing Harvest
September
October
November
December
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Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

0.9"/week · Only during dry spells

📅 Days to Maturity

60–100 days

🧪 Soil pH

Needs 6–7.5 · Your soil: acceptable

🗺️ USDA Zone

Zone 7a

📆 Growing Season

194 days in St. Louis County

Growing Tips for Cabbage in St. Louis County

Direct sow Cabbage outdoors after April 13 in St. Louis County when soil has warmed and frost danger has passed.

Common pests for Cabbage in this region include cabbage worm and flea beetles. Use row covers early in the season and inspect plants weekly.

General growing tips

Start seeds indoors 4-6 weeks before last frost. Space plants 18-24 inches apart. Keep soil evenly moist to prevent heads from splitting.

Companion Planting

Good Companions

Avoid Planting Near

  • Strawberries
  • Tomatoes

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Cabbage in St. Louis County, MO?

St. Louis County is in Zone 7a with an average last frost of April 13. Plan your Cabbage 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 7a. The average last spring frost is April 13 and first fall frost is October 24.

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Your St. Louis County Garden Planner — Free

A 24-page printable planner built for St. Louis County (Zone 7a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

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Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for St. Louis County, MO. Local conditions may vary. Last updated: May 2026.

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.