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

Alachua County, Florida Zone 9a May

What to do in May

Your garden in Alachua County, Florida is working on a schedule, even when you're not. Here's where you should be this May.

Avg. last frost February 23
Avg. first frost November 27
Soil temp (4") 77°F
Watering Moderate
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.

A few tasks this May that'll pay off in June
  • 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.

Alachua County, Florida is in USDA Zone 9a. The average last spring frost is February 23 and the first fall frost is November 27, giving you a growing season of approximately 277 days.

At an elevation of 398 feet, Alachua County receives approximately 50 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.

Alachua County, FL (Zone 9a) Year-round
277 days
Last Spring Frost February 23
277 growing days
First Fall Frost November 27
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Alachua County Soil Profile

Soil Type

Sand

Soil pH

5.2-6.1

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (152 days to spare)
Start indoors: Jan 17 Transplant: Feb 7 🍅 Harvest: Apr 11 – Jun 20
Recommended (50%) ✓ Fits season (151 days to spare)
Start indoors: Jan 26 Transplant: Feb 16 🍅 Harvest: Apr 20 – Jun 29
Safe Start (90%) ✓ Fits season (145 days to spare)
Start indoors: Feb 24 Transplant: Mar 17 🍅 Harvest: May 19 – Jul 28

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 Alachua County

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

Soil pH

Your soil pH (5.2–6.1) overlaps with Fennel (herb)'s range (5.5–7.0), though not a perfect match.

Soil Texture

Sandy soil in Alachua 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 277-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
0.7″/week
Watering frequency 1-2 times/week
Season total 1,617 gal / 100 sq ft
Drought risk

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

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" 2.7" 1.6" 💧 Light watering
Mar 4.3" 2.7" 1.6" 💧 Light watering
Apr 4.3" 2.5" 1.8" 💧 Light watering
May 4.3" 3.2" 1.1" 💧 Light watering
Jun 4.3" 7.5" 0" ✅ Rainfall sufficient
Jul 4.3" 7.4" 0" ✅ Rainfall sufficient
Aug 4.3" 6.3" 0" ✅ Rainfall sufficient
Sep 4.3" 6.8" 0" ✅ Rainfall sufficient
Oct 4.3" 4.6" 0" ✅ Rainfall sufficient
Nov 4.3" 1.9" 2.4" 🚿 Regular watering
Dec 1.8" 0" ❄️ Dormant

Water needs are for active growing months only (Feb–Nov in Alachua 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 6,741 GDD Excellent fit

Fennel (herb) Planting Timeline — Alachua County, FL

Fennel (herb) Planting Calendar

Activity When Date Range
Start Indoors January 26 Jan 26 – Feb 9
Transplant Outdoors February 16 Feb 16 – Mar 2
Direct Sow February 2 Feb 2 – Feb 23
Harvest April 20 Apr 20 – Jun 29
Fall Sowing October 2 Oct 2 – Oct 16

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

Month-by-Month Timeline

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

🗺️ USDA Zone

Zone 9a

📆 Growing Season

277 days in Alachua County

Growing Tips for Fennel (herb) in Alachua County

Direct sow Fennel (herb) outdoors after February 23 in Alachua County when soil has warmed and frost danger has passed.

Sandy soil in Alachua 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 Alachua 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 Alachua County, FL?

Alachua County is in Zone 9a with an average last frost of February 23. Plan your Fennel (herb) planting based on this frost date — see the calendar above for exact timing.

What planting zone is Alachua County, FL?

Alachua County, Florida is in USDA Hardiness Zone 9a. The average last spring frost is February 23 and first fall frost is November 27.

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Your Alachua County Garden Planner — Free

A 24-page printable planner built for Alachua 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 Alachua 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.