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When to Plant Fennel in San Benito County, CA

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 Benito County, California is in USDA Zone 9a. The average last spring frost is February 21 and the first fall frost is November 29, giving you a growing season of approximately 281 days.

At an elevation of 149 feet, San Benito County receives approximately 13 inches of rainfall annually with predominantly loam soil. Summer highs average 94ยฐF, providing good warmth for Fennel during the growing season. With low rainfall, drip irrigation is essential for growing Fennel successfully. Mulch heavily to conserve soil moisture.

San Benito County, CA (Zone 9a) Year-round
281 days
Last Spring Frost February 21
281 growing days
First Fall Frost November 29

San Benito County Soil Profile

Soil Type

Loam

Soil pH

6.5-7.4

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (178 days to spare)
Start indoors: Dec 25 Transplant: Feb 12 🍅 Harvest: Apr 16 – May 28
Recommended (50%) ✓ Fits season (169 days to spare)
Start indoors: Jan 10 Transplant: Feb 28 🍅 Harvest: May 2 – Jun 13
Safe Start (90%) ✓ Fits season (145 days to spare)
Start indoors: Feb 25 Transplant: Apr 15 🍅 Harvest: Jun 17 – Jul 29

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
0.2″/week
You supply
1.0″/week
Watering frequency 2-3 times/week
Season total 2,429 gal / 100 sq ft
Drought risk

Water stress score is 10/10 โ€” consider drought-tolerant varieties and mulching

Fennel needs ~1,538 GDD — county provides 5,781 GDD Excellent fit

Fennel Planting Timeline โ€” San Benito County, CA

Fennel Planting Calendar

Activity When Date Range
Start Indoors January 10 Jan 10 โ€“ Jan 24
Transplant Outdoors February 28 Feb 28 โ€“ Mar 14
Direct Sow February 21 Feb 21 โ€“ Mar 14
Harvest May 2 May 2 โ€“ Jun 13

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

Month-by-Month Timeline

MonthActivities
January Start Indoors
February Transplant Outdoors Direct Sow
March Transplant Outdoors Direct Sow
April โ€”
May Harvest
June Harvest
July โ€”
August โ€”
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 9a

Growing Season

281 days

Growing Tips for San Benito 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 San Benito County, CA?

San Benito County is in Zone 9a with an average last frost of February 21. Plan your Fennel planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is San Benito County, CA?

San Benito County, California is in USDA Hardiness Zone 9a. The average last spring frost is February 21 and first fall frost is November 29.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help San Benito County gardeners in Zone 9a organize planting dates, track what's growing, and never miss a planting window.

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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 San Benito County, CA. Local conditions may vary. Last updated: April 2026.