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When to Plant Fennel in Kitsap County, WA

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.

Kitsap County, Washington is in USDA Zone 8a. The average last spring frost is March 25 and the first fall frost is November 5, giving you a growing season of approximately 225 days.

At an elevation of 264 feet, Kitsap County receives approximately 38 inches of rainfall annually with predominantly silt loam soil. Summer highs average 85ยฐF, providing good warmth for Fennel during the growing season.

Kitsap County, WA (Zone 8a) Long season
225 days
Last Spring Frost March 25
225 growing days
First Fall Frost November 5

Kitsap County Soil Profile

Soil Type

Silt Loam

Soil pH

5.3-6.3

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (104 days to spare)
Start indoors: Jan 30 Transplant: Apr 3 🍅 Harvest: Jun 5 – Jul 17
Recommended (50%) ✓ Fits season (106 days to spare)
Start indoors: Feb 4 Transplant: Apr 8 🍅 Harvest: Jun 10 – Jul 22
Safe Start (90%) ✓ Fits season (108 days to spare)
Start indoors: Feb 25 Transplant: Apr 29 🍅 Harvest: Jul 1 – Aug 12

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 Kitsap County

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

Soil pH

Your soil pH (5.3โ€“6.3) overlaps with Fennel's range (5.5โ€“7.0), though not a perfect match.

Soil Texture

The silt loam soil in Kitsap County is excellent for Fennel โ€” good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is excellent (4.5%) โ€” Fennel will thrive.

How to Plant Fennel

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

Succession Planting Fennel

4
successive plantings in your 225-day season

Sow every 6.9 weeks. Last sowing by Aug 07 to harvest before frost.

Plant Water Budget

Plant needs
0.6″/week
Rainfall provides
0.7″/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 โ€” 5.1" 0" โ„๏ธ Dormant
Feb โ€” 4.5" 0" โ„๏ธ Dormant
Mar 2.6" 4.3" 0" โœ… Rainfall sufficient
Apr 2.6" 2.7" 0" โœ… Rainfall sufficient
May 2.6" 2" 0.6" ๐Ÿ’ง Light watering
Jun 2.6" 1.3" 1.3" ๐Ÿšฟ Regular watering
Jul 2.6" 0.7" 1.9" ๐Ÿšฟ Regular watering
Aug 2.6" 0.7" 1.9" ๐Ÿšฟ Regular watering
Sep 2.6" 1.4" 1.2" ๐Ÿ’ง Light watering
Oct 2.6" 2.9" 0" โœ… Rainfall sufficient
Nov 2.6" 6.5" 0" โœ… Rainfall sufficient
Dec โ€” 6" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Marโ€“Nov in Kitsap County). Supplement amounts are based on average rainfall โ€” 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" โ€” every day above 50ยฐF 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 ~1,031 GDD — county provides 3,093 GDD Excellent fit

Fennel Planting Timeline โ€” Kitsap County, WA

Fennel Planting Calendar

Activity When Date Range
Start Indoors February 4 Feb 4 โ€“ Feb 18
Transplant Outdoors April 8 Apr 8 โ€“ Apr 22
Direct Sow April 1 Apr 1 โ€“ Apr 22
Harvest June 10 Jun 10 โ€“ Jul 22

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

Month-by-Month Timeline

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

Growing Conditions

โ˜€๏ธ Sun

Full Sun (6-8+ hours)

๐Ÿ’ง Water

0.6"/week ยท Natural rainfall sufficient

๐Ÿ“… Days to Maturity

60โ€“90 days

๐Ÿงช Soil pH

Needs 5.5โ€“7 ยท Your soil: acceptable

๐Ÿ—บ๏ธ USDA Zone

Zone 8a

๐Ÿ“† Growing Season

225 days in Kitsap County

Growing Tips for Fennel in Kitsap County

Direct sow Fennel outdoors after March 25 in Kitsap 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 Kitsap County, WA?

Kitsap County is in Zone 8a with an average last frost of March 25. Plan your Fennel planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Kitsap County, WA?

Kitsap County, Washington is in USDA Hardiness Zone 8a. The average last spring frost is March 25 and first fall frost is November 5.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Kitsap County gardeners in Zone 8a organize planting dates, track what's growing, and never miss a planting window.

Get Your Free Garden Planner →

Free download. Plan your entire garden season in minutes.

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