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When to Plant Fennel in Pierce 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.

Pierce County, Washington is in USDA Zone 8a. The average last spring frost is April 13 and the first fall frost is October 30, giving you a growing season of approximately 200 days.

At an elevation of 168 feet, Pierce County receives approximately 48.9 inches of rainfall annually with predominantly silt loam soil. Summer highs average 83ยฐF, so choose short-season varieties of Fennel to ensure they mature before fall.

Pierce County, WA (Zone 8a) Long season
200 days
Last Spring Frost April 13
200 growing days
First Fall Frost October 30

Pierce County Soil Profile

Soil Type

Silt Loam

Soil pH

5.4-6.2

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (73 days to spare)
Start indoors: Feb 14 Transplant: Apr 18 🍅 Harvest: Jun 20 – Aug 1
Recommended (50%) ✓ Fits season (81 days to spare)
Start indoors: Feb 23 Transplant: Apr 27 🍅 Harvest: Jun 29 – Aug 10
Safe Start (90%) ✓ Fits season (73 days to spare)
Start indoors: Mar 28 Transplant: May 30 🍅 Harvest: Aug 1 – Sep 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.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
1.0″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft
Fennel needs ~919 GDD — county provides 2,450 GDD Excellent fit

Fennel Planting Timeline โ€” Pierce County, WA

Fennel Planting Calendar

Activity When Date Range
Start Indoors February 23 Feb 23 โ€“ Mar 9
Transplant Outdoors April 27 Apr 27 โ€“ May 11
Direct Sow April 20 Apr 20 โ€“ May 11
Harvest June 29 Jun 29 โ€“ Aug 10

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

Month-by-Month Timeline

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

Growing Conditions

Sun

Full Sun (6-8+ hours)

Water

Moderate โ€” regular watering

Days to Maturity

60โ€“90 days

Soil pH

5.5 โ€“ 7

USDA Zone

Zone 8a

Growing Season

200 days

Growing Tips for Pierce County

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

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Frequently Asked Questions

When should I plant Fennel in Pierce County, WA?

Pierce County is in Zone 8a with an average last frost of April 13. Plan your Fennel planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Pierce County, WA?

Pierce County, Washington is in USDA Hardiness Zone 8a. The average last spring frost is April 13 and first fall frost is October 30.

๐ŸŒฑ

Plan Your Garden with Confidence

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

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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 Pierce County, WA. Local conditions may vary. Last updated: April 2026.