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When to plant Fennel in Lecompton, KS

For Fennel in Lecompton, the safe spring window opens around April 19 and closes around May 10. Last expected frost is April 12, first fall frost October 25, giving a 196-day growing season.

When to Plant Fennel in Lecompton, KS

Douglas County, Kansas Zone 6b June

This month in Douglas County, Kansas

June rewards gardeners who work with the weather, not against it. Here's how to stay in step this month in Douglas County, Kansas.

Avg. last frost April 12
Avg. first frost October 25
Soil temp (4") 72°F
Watering Low
Pest pressure High
Daylight 14.7 hrs
  1. Get fennel seeds going inside

    Starting these indoors now means sturdy transplants ready the moment your soil warms up.

  2. Start harvesting fennel

    Taste as you pick. The first ripe produce is the best feedback loop you'll get all season.

July 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.

Lecompton, Kansas is in USDA Zone 6b. The average last spring frost is April 12 and the first fall frost is October 25, giving you a growing season of approximately 196 days.

At an elevation of 494 feet, Douglas County receives approximately 27.7 inches of rainfall annually with predominantly loam soil. Summer highs average 90°F, providing good warmth for Fennel during the growing season.

Lecompton, KS (Zone 6b) Moderate season
196 days
Last Spring Frost April 12
196 growing days
First Fall Frost October 25

Lecompton Soil Profile

Soil Type

Loam

Soil pH

6.5-7.6

Drainage

Well Drained

Fennel Planting Risk Windows

Early Start (70% safe) ✓ Fits season (75 days to spare)
Start indoors: Feb 9 Transplant: Apr 20 🍅 Harvest: Jun 22 – Aug 3
Recommended (50%) ✓ Fits season (77 days to spare)
Start indoors: Feb 15 Transplant: Apr 26 🍅 Harvest: Jun 28 – Aug 9
Safe Start (90%) ✓ Fits season (79 days to spare)
Start indoors: Mar 1 Transplant: May 10 🍅 Harvest: Jul 12 – 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 Lecompton

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

Soil pH

Your soil pH (6.5–7.6) is more alkaline than Fennel prefers (5.5–7.0). Add sulfur or peat moss to lower pH.

Soil Texture

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

Organic Matter

Organic matter is moderate (3.2%). Annual compost additions will help Fennel.

How to Plant Fennel

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

Succession Planting Fennel

3
successive plantings in your 196-day season

Sow every 6.9 weeks. Last sowing by Jul 27 to harvest before frost.

Fennel Water Budget

Plant needs
0.6″/week
Rainfall provides
0.6″/week
You supply
0.0″/week
Watering frequency Only during dry spells
Season total 13 gal / 100 sq ft
Drought risk

Water stress score is 6/10 — consider drought-tolerant varieties and mulching

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 0.7" 0" ❄️ Dormant
Feb 1" 0" ❄️ Dormant
Mar 1.8" 0" ❄️ Dormant
Apr 2.6" 2.7" 0" ✅ Rainfall sufficient
May 2.6" 4.3" 0" ✅ Rainfall sufficient
Jun 2.6" 4" 0" ✅ Rainfall sufficient
Jul 2.6" 3.9" 0" ✅ Rainfall sufficient
Aug 2.6" 3.6" 0" ✅ Rainfall sufficient
Sep 2.6" 2.4" 0.2" 💧 Light watering
Oct 2.6" 1.7" 0.9" 💧 Light watering
Nov 0.9" 0" ❄️ Dormant
Dec 0.6" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Douglas 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 ~1,312 GDD — county provides 3,430 GDD Excellent fit

Fennel Planting Timeline — Lecompton, KS

Fennel Planting Calendar

Activity When Date Range
Start Indoors February 15 Feb 15 – Mar 1
Transplant Outdoors April 26 Apr 26 – May 10
Direct Sow April 19 Apr 19 – May 10
Harvest June 28 Jun 28 – Aug 9

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

Month-by-Month Timeline

MonthActivities
January
February Start Indoors
March Start Indoors
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 · Only during dry spells

📅 Days to Maturity

60–90 days

🧪 Soil pH

Needs 5.5–7 · Your soil: too_alkaline

🗺️ USDA Zone

Zone 6b

📆 Growing Season

196 days in Douglas County

Growing Tips for Fennel in Lecompton

Direct sow Fennel outdoors after April 12 in Douglas 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 →

When should I plant Fennel in Lecompton, KS?

In Lecompton, KS, plant Fennel after the last frost (around April 12) and before the first frost (around October 25). Best results when soil holds above 50°F.

What growing zone is Lecompton, KS for Fennel?

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

Can Fennel grow in Lecompton's climate?

Yes — Fennel grows well in Lecompton's temperate climate. Lecompton averages a 196-day frost-free season, with last frost around April 12 and first frost around October 25.

🌱

Your Douglas County Garden Planner — Free

A 22-page printable planner built for Douglas 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 Douglas County, KS. Local conditions may vary. Last updated: June 2026.