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When to Plant Fennel in Lewis 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.

Lewis County, Washington is in USDA Zone 7b. The average last spring frost is April 25 and the first fall frost is October 24, giving you a growing season of approximately 182 days.

At an elevation of 327 feet, Lewis County receives approximately 37.3 inches of rainfall annually with predominantly silt loam soil. Summer highs average 86ยฐF, providing good warmth for Fennel during the growing season.

Lewis County, WA (Zone 7b) Moderate season
182 days
Last Spring Frost April 25
182 growing days
First Fall Frost October 24

Lewis County Soil Profile

Soil Type

Silt Loam

Soil pH

5.6-6.2

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (51 days to spare)
Start indoors: Feb 23 Transplant: Apr 27 🍅 Harvest: Jun 29 – Aug 10
Recommended (50%) ✓ Fits season (63 days to spare)
Start indoors: Mar 7 Transplant: May 9 🍅 Harvest: Jul 11 – Aug 22
Safe Start (90%) ✓ Fits season (31 days to spare)
Start indoors: May 6 Transplant: Jul 8 🍅 Harvest: Sep 9 – Oct 21

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
0.9″/week
You supply
0.1″/week
Watering frequency Only during dry spells
Season total 226 gal / 100 sq ft
Fennel needs ~1,088 GDD — county provides 2,639 GDD Excellent fit

Fennel Planting Timeline โ€” Lewis County, WA

Fennel Planting Calendar

Activity When Date Range
Start Indoors March 7 Mar 7 โ€“ Mar 21
Transplant Outdoors May 9 May 9 โ€“ May 23
Direct Sow May 2 May 2 โ€“ May 23
Harvest July 11 Jul 11 โ€“ Aug 22

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

Month-by-Month Timeline

MonthActivities
January โ€”
February โ€”
March Start Indoors
April โ€”
May Transplant Outdoors Direct Sow
June โ€”
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 7b

Growing Season

182 days

Growing Tips for Lewis 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 Lewis County, WA?

Lewis County is in Zone 7b with an average last frost of April 25. Plan your Fennel planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Lewis County, WA?

Lewis County, Washington is in USDA Hardiness Zone 7b. The average last spring frost is April 25 and first fall frost is October 24.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Lewis County gardeners in Zone 7b 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 Lewis County, WA. Local conditions may vary. Last updated: April 2026.