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When to plant Fennel in Cole County, MO

Fennel planted in Cole County between April 14 and May 5 matures in 60–90 days — well before the October 28 first frost.

When to Plant Fennel in Cole County, MO

Cole County, Missouri Zone 6b July

Your July gardening checklist

Welcome to July in Zone 6b. These are the moves that will have the biggest impact on your growing season.

Avg. last frost April 7
Avg. first frost October 28
Soil temp (4") 81°F
Watering Low
Pest pressure High
Daylight 14.4 hrs
  1. Collect fennel at their peak

    The more you pick, the more the plant produces. Letting fruit overripen tells the plant it's time to stop.

August prep starts now
  • First harvests: fennel

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Florence fennel is grown for its swollen bulb-like stem base, which has a mild anise flavor. It is crisp raw in salads and sweet when roasted or braised.

Cole County, Missouri is in USDA Zone 6b. The average last spring frost is April 7 and the first fall frost is October 28, giving you a growing season of approximately 204 days.

At an elevation of 614 feet, Cole County receives approximately 39.4 inches of rainfall annually with predominantly silt loam soil. Summer highs average 88°F, providing good warmth for Fennel during the growing season.

Cole County, MO (Zone 6b) Long season
204 days
Last Spring Frost April 7
204 growing days
First Fall Frost October 28

Cole County Soil Profile

Soil Type

Silt Loam

Soil pH

5.4-6.9

Drainage

Well Drained

Fennel Planting Risk Windows

Early Start (70% safe) ✓ Fits season (87 days to spare)
Start indoors: Feb 3 Transplant: Apr 14 🍅 Harvest: Jun 16 – Jul 28
Recommended (50%) ✓ Fits season (85 days to spare)
Start indoors: Feb 10 Transplant: Apr 21 🍅 Harvest: Jun 23 – Aug 4
Safe Start (90%) ✓ Fits season (86 days to spare)
Start indoors: Feb 25 Transplant: May 6 🍅 Harvest: Jul 8 – Aug 19

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 Cole County

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

Soil pH

Your soil pH (5.4–6.9) overlaps with Fennel's range (5.5–7.0), though not a perfect match.

Soil Texture

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

Drainage

Drainage is adequate for Fennel.

Organic Matter

Organic matter is moderate (3.1%). Annual compost additions will help Fennel.

How to Plant Fennel

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

Succession Planting Fennel

4
successive plantings in your 204-day season

Sow every 6.9 weeks. Last sowing by Jul 30 to harvest before frost.

Fennel Water Budget

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

Monthly Watering Guide for Fennel

Fennel 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 Fennel Needs Rainfall You Supplement Action
Jan 1.6" 0" ❄️ Dormant
Feb 1.5" 0" ❄️ Dormant
Mar 2.4" 0" ❄️ Dormant
Apr 2.6" 4.4" 0" ✅ Rainfall sufficient
May 2.6" 4.6" 0" ✅ Rainfall sufficient
Jun 2.6" 5.5" 0" ✅ Rainfall sufficient
Jul 2.6" 4.2" 0" ✅ Rainfall sufficient
Aug 2.6" 4.1" 0" ✅ Rainfall sufficient
Sep 2.6" 3.6" 0" ✅ Rainfall sufficient
Oct 2.6" 2.8" 0" ✅ Rainfall sufficient
Nov 2.6" 0" ❄️ Dormant
Dec 1.9" 0" ❄️ Dormant

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

Fennel 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.

Fennel needs ~1,200 GDD — county provides 3,264 GDD Excellent fit

Fennel Planting Timeline — Cole County, MO

Fennel Planting Calendar

Activity When Date Range
Start Indoors February 10 Feb 10 – Feb 24
Transplant Outdoors April 21 Apr 21 – May 5
Direct Sow April 14 Apr 14 – May 5
Harvest June 23 Jun 23 – Aug 4

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

0.6"/week · Natural rainfall sufficient

📅 Days to Maturity

60–90 days

🧪 Soil pH

Needs 5.5–7 · Your soil: acceptable

🗺️ USDA Zone

Zone 6b

📆 Growing Season

204 days in Cole County

Growing Tips for Fennel in Cole County

Direct sow Fennel outdoors after April 07 in Cole County when soil has warmed and frost danger has passed.

Common pests for Fennel in this region include carrot rust fly and parsleyworm. Use row covers early in the season and inspect plants weekly.

General growing tips

Direct sow in late summer for fall harvest to reduce bolting. Hill soil around bulbs as they enlarge. Harvest when bulbs are tennis-ball sized before they elongate.

Companion Planting

Good Companions

Avoid Planting Near

  • Tomatoes
  • Peppers
  • Beans

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Fennel in Cole County, MO?

Cole County is in Zone 6b with an average last frost of April 7. Plan your Fennel planting based on this frost date — see the calendar above for exact timing.

What planting zone is Cole County, MO?

Cole County, Missouri is in USDA Hardiness Zone 6b. The average last spring frost is April 7 and first fall frost is October 28.

When should I plant Fennel in Cole County, MO?

In Cole County, MO, plant Fennel after the last frost (around April 7) and before the first frost (around October 28). Best results when soil holds above 50°F.

What growing zone is Cole County, MO for Fennel?

Cole County sits in USDA Zone 6b. Fennel grows reliably in zones 4a through 10b, so it's a good fit here.

Can Fennel grow in Cole County's climate?

Yes — Fennel grows well in Cole County's temperate climate. Cole County averages a 204-day frost-free season, with last frost around April 7 and first frost around October 28.

🌱

Your Cole County Garden Planner — Free

A 22-page printable planner built for Cole 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.

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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 Cole County, MO. Local conditions may vary. Last updated: July 2026.

Sources & credits

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