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When to Plant Rutabaga in Mercer County, MO

Mercer County, Missouri Zone 5b May

This month in Mercer County, Missouri

A quick May briefing for Mercer County, Missouri gardeners — what's urgent, what's next, and what can wait.

Avg. last frost April 20
Avg. first frost October 14
Soil temp (4") 59°F
Watering Low
Pest pressure Low
Daylight 14.2 hrs
June prep starts now
  • First harvests: rutabaga

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Rutabagas are a cross between turnips and cabbage, producing large yellow-fleshed roots with a sweet, mild flavor. They are excellent mashed, roasted, or in stews.

Mercer County, Missouri is in USDA Zone 5b. The average last spring frost is April 20 and the first fall frost is October 14, giving you a growing season of approximately 177 days.

At an elevation of 523 feet, Mercer County receives approximately 41.7 inches of rainfall annually with predominantly silt loam soil. Summer highs average 87°F, providing good warmth for Rutabaga during the growing season.

Mercer County, MO (Zone 5b) Moderate season
177 days
Last Spring Frost April 20
177 growing days
First Fall Frost October 14
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Mercer County Soil Profile

Soil Type

Silt Loam

Soil pH

5.6-6.8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (61 days to spare)
Transplant: Apr 12 🍅 Harvest: Jul 5 – Aug 9
Recommended (50%) ✓ Fits season (58 days to spare)
Transplant: Apr 20 🍅 Harvest: Jul 13 – Aug 17
Safe Start (90%) ✓ Fits season (61 days to spare)
Transplant: May 4 🍅 Harvest: Jul 27 – Aug 31

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 Mercer County

How your county's soil matches Rutabaga's growing requirements.

Soil pH

Your soil pH (5.6–6.8) overlaps with Rutabaga's range (6.0–7.5), though not a perfect match.

Soil Texture

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

Drainage

Drainage is adequate for Rutabaga.

Organic Matter

Organic matter is moderate (2.9%). Annual compost additions will help Rutabaga.

How to Plant Rutabaga

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 Rutabaga

2
successive plantings in your 177-day season

Sow every 9.1 weeks. Last sowing by Jul 06 to harvest before frost.

For a dedicated fall crop, sow by Aug 05.

Plant Water Budget

Plant needs
0.7″/week
Rainfall provides
1.0″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft

Monthly Watering Guide for Rutabaga

Rutabaga needs approximately 0.7 inches of water per week (3" per month). Here's how your county's rainfall compares month by month.

Month Rutabaga Needs Rainfall You Supplement Action
Jan 1.7" 0" ❄️ Dormant
Feb 2" 0" ❄️ Dormant
Mar 3.2" 0" ❄️ Dormant
Apr 3" 4.3" 0" ✅ Rainfall sufficient
May 3" 4.8" 0" ✅ Rainfall sufficient
Jun 3" 5.1" 0" ✅ Rainfall sufficient
Jul 3" 4" 0" ✅ Rainfall sufficient
Aug 3" 4.4" 0" ✅ Rainfall sufficient
Sep 3" 3.6" 0" ✅ Rainfall sufficient
Oct 3" 3.2" 0" ✅ Rainfall sufficient
Nov 2.7" 0" ❄️ Dormant
Dec 2.5" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Mercer County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.

Rutabaga 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.

Rutabaga needs ~1,372 GDD — county provides 2,699 GDD Excellent fit

Rutabaga Planting Timeline — Mercer County, MO

Rutabaga Planting Calendar

Activity When Date Range
Direct Sow April 6 Apr 6 – Apr 27
Harvest June 29 Jun 29 – Aug 3
Fall Sowing August 5 Aug 5 – Aug 19

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

Month-by-Month Timeline

MonthActivities
January
February
March
April 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

0.7"/week · Natural rainfall sufficient

📅 Days to Maturity

80–100 days

🧪 Soil pH

Needs 6–7.5 · Your soil: acceptable

🗺️ USDA Zone

Zone 5b

📆 Growing Season

177 days in Mercer County

Growing Tips for Rutabaga in Mercer County

Direct sow Rutabaga outdoors after April 20 in Mercer County when soil has warmed and frost danger has passed.

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

General growing tips

Direct sow in early summer for fall harvest. Thin seedlings to 6-8 inches apart. Flavor improves significantly after a few light frosts.

Companion Planting

Good Companions

Avoid Planting Near

  • Potatoes

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Rutabaga in Mercer County, MO?

Mercer County is in Zone 5b with an average last frost of April 20. Plan your Rutabaga planting based on this frost date — see the calendar above for exact timing.

What planting zone is Mercer County, MO?

Mercer County, Missouri is in USDA Hardiness Zone 5b. The average last spring frost is April 20 and first fall frost is October 14.

🌱

Your Mercer County Garden Planner — Free

A 24-page printable planner built for Mercer 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.

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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 Mercer 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.