When to Plant Fennel in San Juan 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.
San Juan County, Washington is in USDA Zone 8a. The average last spring frost is March 26 and the first fall frost is November 3, giving you a growing season of approximately 222 days.
At an elevation of 371 feet, San Juan County receives approximately 40.9 inches of rainfall annually with predominantly silt loam soil. Summer highs average 82°F, so choose short-season varieties of Fennel to ensure they mature before fall.
San Juan County Soil Profile
Soil Type
Silt Loam
Soil pH
5.4-6.4
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.
Plant Water Budget
Fennel Planting Timeline — San Juan County, WA
Fennel Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | February 5 | Feb 5 – Feb 19 |
| Transplant Outdoors | April 9 | Apr 9 – Apr 23 |
| Direct Sow | April 2 | Apr 2 – Apr 23 |
| Harvest | June 11 | Jun 11 – Jul 23 |
Plant 1" deep · 15" apart · Rows 24" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | Start Indoors |
| March | — |
| April | Transplant Outdoors Direct Sow |
| May | — |
| June | Harvest |
| July | Harvest |
| August | — |
| September | — |
| October | — |
| November | — |
| December | — |
Growing Conditions
Sun
Full Sun (6-8+ hours)
Water
Moderate — regular watering
Days to Maturity
60–90 days
Soil pH
5.5 – 7
USDA Zone
Zone 8a
Growing Season
222 days
Growing Tips for San Juan 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
Level Up Your Garden
Fennel in Other Locations
Frequently Asked Questions
When should I plant Fennel in San Juan County, WA?
San Juan County is in Zone 8a with an average last frost of March 26. Plan your Fennel planting based on this frost date — see the calendar above for exact timing.
What planting zone is San Juan County, WA?
San Juan County, Washington is in USDA Hardiness Zone 8a. The average last spring frost is March 26 and first fall frost is November 3.
Plan Your Garden with Confidence
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