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When to Plant Fennel (herb) in Clay County, FL

Clay County, Florida Zone 9a May

Your May gardening checklist

May is a pivotal month for Clay County, Florida gardens. Focus on these tasks first and you'll set up the rest of the season for success.

Avg. last frost February 18
Avg. first frost November 27
Soil temp (4") 78°F
Watering Low
Pest pressure High
Daylight 13.5 hrs
  1. It's harvest week for fennel (herb)

    Don't tug. Use scissors or pruners for clean cuts — torn stems invite disease.

June will be here before you know it — start on
  • First harvests: fennel (herb)

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Herb fennel is grown for its aromatic leaves, stalks, and seeds rather than a bulb. It has a strong anise flavor and its flowers attract beneficial insects.

Clay County, Florida is in USDA Zone 9a. The average last spring frost is February 18 and the first fall frost is November 27, giving you a growing season of approximately 282 days.

At an elevation of 122 feet, Clay County receives approximately 54.3 inches of rainfall annually with predominantly sand soil. Summer highs average 99°F, so Fennel (herb) may need afternoon shade and extra watering during peak heat. Sandy soil warms quickly in spring — great for early planting — but Fennel (herb) will need more frequent watering and organic matter to retain nutrients. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Fennel (herb) root diseases.

Clay County, FL (Zone 9a) Year-round
282 days
Last Spring Frost February 18
282 growing days
First Fall Frost November 27

Clay County Soil Profile

Soil Type

Sand

Soil pH

5-5.8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (155 days to spare)
Start indoors: Jan 12 Transplant: Feb 2 🍅 Harvest: Apr 6 – Jun 15
Recommended (50%) ✓ Fits season (156 days to spare)
Start indoors: Jan 21 Transplant: Feb 11 🍅 Harvest: Apr 15 – Jun 24
Safe Start (90%) ✓ Fits season (147 days to spare)
Start indoors: Feb 22 Transplant: Mar 15 🍅 Harvest: May 17 – Jul 26

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 Clay County

How your county's soil matches Fennel (herb)'s growing requirements.

Soil pH

Your soil pH (5.0–5.8) is more acidic than Fennel (herb) prefers (5.5–7.0). Add garden lime to raise pH.

Soil Texture

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

Drainage

Drainage is adequate for Fennel (herb).

Organic Matter

Organic matter is low (1.6%). Add 2-3 inches of compost before planting Fennel (herb).

How to Plant Fennel (herb)

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

Fall planting: Sow 8 weeks before your first frost date for a fall harvest.

Succession Planting Fennel (herb)

5
successive plantings in your 282-day season

Sow every 6.9 weeks. Last sowing by Aug 29 to harvest before frost.

For a dedicated fall crop, sow by Oct 02.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.8″/week
You supply
0.5″/week
Watering frequency 1-2 times/week
Season total 1,245 gal / 100 sq ft

Monthly Watering Guide for Fennel (herb)

Fennel (herb) needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.

Month Fennel (herb) Needs Rainfall You Supplement Action
Jan 2.6" 0" ❄️ Dormant
Feb 4.3" 3" 1.3" 💧 Light watering
Mar 4.3" 3.1" 1.2" 💧 Light watering
Apr 4.3" 2.5" 1.8" 💧 Light watering
May 4.3" 4" 0.3" 💧 Light watering
Jun 4.3" 8.5" 0" ✅ Rainfall sufficient
Jul 4.3" 7.4" 0" ✅ Rainfall sufficient
Aug 4.3" 7.4" 0" ✅ Rainfall sufficient
Sep 4.3" 6.6" 0" ✅ Rainfall sufficient
Oct 4.3" 5.1" 0" ✅ Rainfall sufficient
Nov 4.3" 2.1" 2.2" 🚿 Regular watering
Dec 2.2" 0" ❄️ Dormant

Water needs are for active growing months only (Feb–Nov in Clay County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.

Fennel (herb) 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 (herb) needs ~1,819 GDD — county provides 6,862 GDD Excellent fit

Fennel (herb) Planting Timeline — Clay County, FL

Fennel (herb) Planting Calendar

Activity When Date Range
Start Indoors January 21 Jan 21 – Feb 4
Transplant Outdoors February 11 Feb 11 – Feb 25
Direct Sow January 28 Jan 28 – Feb 18
Harvest April 15 Apr 15 – Jun 24
Fall Sowing October 2 Oct 2 – Oct 16

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

Month-by-Month Timeline

MonthActivities
January Start Indoors Direct Sow
February Start Indoors Transplant Outdoors Direct Sow
March
April Harvest
May Harvest
June Harvest
July
August
September
October Fall Sowing
November
December

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · 1-2 times/week

📅 Days to Maturity

60–90 days

🧪 Soil pH

Needs 5.5–7 · Your soil: too_acidic

🗺️ USDA Zone

Zone 9a

📆 Growing Season

282 days in Clay County

Growing Tips for Fennel (herb) in Clay County

Direct sow Fennel (herb) outdoors after February 18 in Clay County when soil has warmed and frost danger has passed.

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

With summer highs reaching 99°F in Clay County, provide afternoon shade for Fennel (herb) and water deeply in the morning.

Common pests for Fennel (herb) 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 spring or fall. Unlike Florence fennel, herb fennel does not form a bulb. Harvest fronds as needed and seeds when they turn brown. Self-sows readily.

Companion Planting

Good Companions

Avoid Planting Near

  • Tomatoes
  • Peppers
  • Green Beans

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Fennel (herb) in Clay County, FL?

Clay County is in Zone 9a with an average last frost of February 18. Plan your Fennel (herb) planting based on this frost date — see the calendar above for exact timing.

What planting zone is Clay County, FL?

Clay County, Florida is in USDA Hardiness Zone 9a. The average last spring frost is February 18 and first fall frost is November 27.

🌱

Your Clay County Garden Planner — Free

A 24-page printable planner built for Clay 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 Clay 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.