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When to Plant Fennel in Santa Rosa County, FL

Santa Rosa County, Florida Zone 9a May

What to do in May

Your Santa Rosa County, Florida garden is entering a new phase. Here's what's on the schedule for May and why each task matters now.

Avg. last frost March 6
Avg. first frost November 21
Soil temp (4") 71°F
Watering Moderate
Pest pressure High
Daylight 13.6 hrs
  1. It's harvest week for fennel

    Check every 1–2 days. Many of these get tough or go to seed if you wait too long.

Coming up in June — start thinking about
  • First harvests: fennel

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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.

Santa Rosa County, Florida is in USDA Zone 9a. The average last spring frost is March 6 and the first fall frost is November 21, giving you a growing season of approximately 260 days.

At an elevation of 104 feet, Santa Rosa County receives approximately 55 inches of rainfall annually with predominantly sand soil. Summer highs average 91°F, providing good warmth for Fennel during the growing season. Sandy soil warms quickly in spring — great for early planting — but Fennel will need more frequent watering and organic matter to retain nutrients. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Fennel root diseases.

Santa Rosa County, FL (Zone 9a) Long season
260 days
Last Spring Frost March 6
260 growing days
First Fall Frost November 21

Santa Rosa County Soil Profile

Soil Type

Sand

Soil pH

5.1-5.8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (147 days to spare)
Start indoors: Jan 18 Transplant: Mar 8 🍅 Harvest: May 10 – Jun 21
Recommended (50%) ✓ Fits season (148 days to spare)
Start indoors: Jan 23 Transplant: Mar 13 🍅 Harvest: May 15 – Jun 26
Safe Start (90%) ✓ Fits season (148 days to spare)
Start indoors: Feb 13 Transplant: Apr 3 🍅 Harvest: Jun 5 – Jul 17

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 Santa Rosa County

How your county's soil matches Fennel's growing requirements.

Soil pH

Your soil pH (5.1–5.8) is more acidic than Fennel prefers (5.5–7.0). Add garden lime to raise pH.

Soil Texture

Sandy soil in Santa Rosa County warms quickly in spring but drains fast. Fennel will need more frequent watering and regular compost additions to retain nutrients.

Drainage

Drainage is adequate for Fennel.

Organic Matter

Organic matter is low (1.7%). Add 2-3 inches of compost before planting Fennel.

How to Plant Fennel

1"
Planting Depth
15"
Between Plants
24"
Between Rows

Succession Planting Fennel

5
successive plantings in your 260-day season

Sow every 6.9 weeks. Last sowing by Aug 23 to harvest before frost.

Plant Water Budget

Plant needs
0.6″/week
Rainfall provides
0.9″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft
Drought risk

Water stress score is 6/10 — consider drought-tolerant varieties and mulching

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 2.9" 0" ❄️ Dormant
Feb 3" 0" ❄️ Dormant
Mar 2.6" 3.1" 0" ✅ Rainfall sufficient
Apr 2.6" 2.3" 0.3" 💧 Light watering
May 2.6" 3.2" 0" ✅ Rainfall sufficient
Jun 2.6" 7.5" 0" ✅ Rainfall sufficient
Jul 2.6" 7.9" 0" ✅ Rainfall sufficient
Aug 2.6" 8.6" 0" ✅ Rainfall sufficient
Sep 2.6" 7.9" 0" ✅ Rainfall sufficient
Oct 2.6" 4.4" 0" ✅ Rainfall sufficient
Nov 2.6" 2" 0.6" 💧 Light watering
Dec 2.3" 0" ❄️ Dormant

Water needs are for active growing months only (Mar–Nov in Santa Rosa 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 needs ~1,369 GDD — county provides 4,745 GDD Excellent fit

Fennel Planting Timeline — Santa Rosa County, FL

Fennel Planting Calendar

Activity When Date Range
Start Indoors January 23 Jan 23 – Feb 6
Transplant Outdoors March 13 Mar 13 – Mar 27
Direct Sow March 6 Mar 6 – Mar 27
Harvest May 15 May 15 – Jun 26

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

Month-by-Month Timeline

MonthActivities
January Start Indoors
February Start Indoors
March Transplant Outdoors Direct Sow
April
May Harvest
June Harvest
July
August
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: too_acidic

🗺️ USDA Zone

Zone 9a

📆 Growing Season

260 days in Santa Rosa County

Growing Tips for Fennel in Santa Rosa County

Direct sow Fennel outdoors after March 06 in Santa Rosa County when soil has warmed and frost danger has passed.

Sandy soil in Santa Rosa County dries quickly — mulch Fennel with 2-3 inches of straw and water deeply 2-3 times per week rather than lightly every day.

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

  • Tomatoes
  • Peppers
  • Beans

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Fennel in Santa Rosa County, FL?

Santa Rosa County is in Zone 9a with an average last frost of March 6. Plan your Fennel planting based on this frost date — see the calendar above for exact timing.

What planting zone is Santa Rosa County, FL?

Santa Rosa County, Florida is in USDA Hardiness Zone 9a. The average last spring frost is March 6 and first fall frost is November 21.

🌱

Your Santa Rosa County Garden Planner — Free

A 24-page printable planner built for Santa Rosa County (Zone 9a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

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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 Santa Rosa County, FL. Local conditions may vary. Last updated: May 2026.

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.