When to Plant Fennel in Pierce County, WA
Your April gardening checklist
A quick April briefing for Pierce County, Washington gardeners — what's urgent, what's next, and what can wait.
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Time to transplant fennel
Water the tray well an hour before you transplant. Roots slide out cleanly and settle in faster.
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Direct-sow fennel
Rake a smooth bed, make a shallow furrow, drop seeds at the spacing on the packet, water gently, walk away.
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 83°F, so choose short-season varieties of Fennel to ensure they mature before fall.
Pierce County Soil Profile
Soil Type
Silt Loam
Soil pH
5.4-6.2
Drainage
Well Drained
Plant Planting Risk Windows
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 Pierce County
How your county's soil matches Fennel's growing requirements.
Soil pH
Your soil pH (5.4–6.2) overlaps with Fennel's range (5.5–7.0), though not a perfect match.
Soil Texture
The silt loam soil in Pierce County is excellent for Fennel — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is excellent (4.4%) — Fennel will thrive.
How to Plant Fennel
Succession Planting Fennel
Sow every 6.9 weeks. Last sowing by Aug 01 to harvest before frost.
Plant Water Budget
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 | — | 6.8" | 0" | ❄️ Dormant |
| Feb | — | 5.7" | 0" | ❄️ Dormant |
| Mar | — | 4.4" | 0" | ❄️ Dormant |
| Apr | 2.6" | 4.1" | 0" | ✅ Rainfall sufficient |
| May | 2.6" | 2.8" | 0" | ✅ Rainfall sufficient |
| Jun | 2.6" | 2" | 0.6" | 💧 Light watering |
| Jul | 2.6" | 0.9" | 1.7" | 🚿 Regular watering |
| Aug | 2.6" | 0.9" | 1.7" | 🚿 Regular watering |
| Sep | 2.6" | 2" | 0.6" | 💧 Light watering |
| Oct | 2.6" | 4.7" | 0" | ✅ Rainfall sufficient |
| Nov | — | 7.8" | 0" | ❄️ Dormant |
| Dec | — | 6.8" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Oct in Pierce 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 Planting Timeline — Pierce County, WA
Fennel Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | February 23 | Feb 23 – Mar 9 |
| Transplant Outdoors | April 27 | Apr 27 – May 11 |
| Direct Sow | April 20 | Apr 20 – May 11 |
| Harvest | June 29 | Jun 29 – Aug 10 |
Plant 1" deep · 15" apart · Rows 24" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| 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 · Natural rainfall sufficient
📅 Days to Maturity
60–90 days
🧪 Soil pH
Needs 5.5–7 · Your soil: acceptable
🗺️ USDA Zone
Zone 8a
📆 Growing Season
200 days in Pierce County
Growing Tips for Fennel in Pierce County
Direct sow Fennel outdoors after April 13 in Pierce 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
Check more plant combinations with our Companion Planting Checker →
Fennel in Other Locations
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 — 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.
Your Pierce County Garden Planner — Free
A 24-page printable planner built for Pierce County (Zone 8a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.