Blog

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

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.

Flagler County, Florida is in USDA Zone 9a. The average last spring frost is February 5 and the first fall frost is December 17, giving you a growing season of approximately 315 days.

At an elevation of 134 feet, Flagler County receives approximately 54.2 inches of rainfall annually with predominantly sand soil. Summer highs average 99ยฐF, so Fennel (herb) may need afternoon shade and extra watering during peak heat. Sandy soil warms quickly in spring โ€” great for early planting โ€” 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.

Flagler County, FL (Zone 9a) Year-round
315 days
Last Spring Frost February 5
315 growing days
First Fall Frost December 17

Flagler County Soil Profile

Soil Type

Sand

Soil pH

5.1-5.7

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (194 days to spare)
Start indoors: Dec 25 Transplant: Jan 15 🍅 Harvest: Mar 19 – May 28
Recommended (50%) ✓ Fits season (189 days to spare)
Start indoors: Jan 8 Transplant: Jan 29 🍅 Harvest: Apr 2 – Jun 11
Safe Start (90%) ✓ Fits season (175 days to spare)
Start indoors: Jan 31 Transplant: Feb 21 🍅 Harvest: Apr 25 – Jul 4

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 Flagler County

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

Soil pH

Your soil pH (5.1โ€“5.7) is more acidic than Fennel (herb) prefers (5.5โ€“7.0). Add garden lime to raise pH.

Soil Texture

Sandy soil in Flagler 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)

6
successive plantings in your 315-day season

Sow every 6.9 weeks. Last sowing by Sep 18 to harvest before frost.

For a dedicated fall crop, sow by Oct 22.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.7″/week
You supply
0.6″/week
Watering frequency 1-2 times/week
Season total 1,630 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 โ€” 2.7" 0" โ„๏ธ Dormant
Feb 4.3" 2.5" 1.8" ๐Ÿ’ง Light watering
Mar 4.3" 3" 1.3" ๐Ÿ’ง Light watering
Apr 4.3" 2.2" 2.1" ๐Ÿ’ง Light watering
May 4.3" 3.7" 0.6" ๐Ÿ’ง Light watering
Jun 4.3" 8.8" 0" โœ… Rainfall sufficient
Jul 4.3" 7.7" 0" โœ… Rainfall sufficient
Aug 4.3" 7.4" 0" โœ… Rainfall sufficient
Sep 4.3" 6.9" 0" โœ… Rainfall sufficient
Oct 4.3" 4.7" 0" โœ… Rainfall sufficient
Nov 4.3" 2" 2.3" ๐Ÿšฟ Regular watering
Dec 4.3" 2.5" 1.8" ๐Ÿ’ง Light watering

Water needs are for active growing months only (Febโ€“Dec in Flagler County). Supplement amounts are based on average rainfall โ€” 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" โ€” every day above 50ยฐF 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 7,663 GDD Excellent fit

Fennel (herb) Planting Timeline โ€” Flagler County, FL

Fennel (herb) Planting Calendar

Activity When Date Range
Start Indoors January 8 Jan 8 โ€“ Jan 22
Transplant Outdoors January 29 Jan 29 โ€“ Feb 12
Direct Sow January 15 Jan 15 โ€“ Feb 5
Harvest April 2 Apr 2 โ€“ Jun 11
Fall Sowing October 22 Oct 22 โ€“ Nov 5

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

Month-by-Month Timeline

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

Growing Conditions

โ˜€๏ธ Sun

Full Sun (6-8+ hours)

๐Ÿ’ง Water

1"/week ยท 1-2 times/week

๐Ÿ“… Days to Maturity

60โ€“90 days

๐Ÿงช Soil pH

Needs 5.5โ€“7 ยท Your soil: too_acidic

๐Ÿ—บ๏ธ USDA Zone

Zone 9a

๐Ÿ“† Growing Season

315 days in Flagler County

Growing Tips for Fennel (herb) in Flagler County

Direct sow Fennel (herb) outdoors after February 05 in Flagler County when soil has warmed and frost danger has passed.

Sandy soil in Flagler County dries quickly โ€” 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 99ยฐF in Flagler 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 Flagler County, FL?

Flagler County is in Zone 9a with an average last frost of February 5. Plan your Fennel (herb) planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Flagler County, FL?

Flagler County, Florida is in USDA Hardiness Zone 9a. The average last spring frost is February 5 and first fall frost is December 17.

๐ŸŒฑ

Plan Your Garden with Confidence

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

Get Your Free Garden Planner →

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 Flagler County, FL. Local conditions may vary. Last updated: April 2026.