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When to Plant Fennel (herb) in Sumter 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.

Sumter County, Florida is in USDA Zone 9a. The average last spring frost is February 6 and the first fall frost is December 6, giving you a growing season of approximately 303 days.

At an elevation of 463 feet, Sumter County receives approximately 60.9 inches of rainfall annually with predominantly sand soil. Summer highs average 96ยฐF, 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.

Sumter County, FL (Zone 9a) Year-round
303 days
Last Spring Frost February 6
303 growing days
First Fall Frost December 6

Sumter County Soil Profile

Soil Type

Sand

Soil pH

5-6.1

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (180 days to spare)
Start indoors: Dec 27 Transplant: Jan 17 🍅 Harvest: Mar 21 – May 30
Recommended (50%) ✓ Fits season (177 days to spare)
Start indoors: Jan 9 Transplant: Jan 30 🍅 Harvest: Apr 3 – Jun 12
Safe Start (90%) ✓ Fits season (170 days to spare)
Start indoors: Feb 4 Transplant: Feb 25 🍅 Harvest: Apr 29 – Jul 8

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 Sumter County

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

Soil pH

Your soil pH (5.0โ€“6.1) overlaps with Fennel (herb)'s range (5.5โ€“7.0), though not a perfect match.

Soil Texture

Sandy soil in Sumter 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 (1.4%). 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 303-day season

Sow every 6.9 weeks. Last sowing by Sep 07 to harvest before frost.

For a dedicated fall crop, sow by Oct 11.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.8″/week
You supply
0.6″/week
Watering frequency 1-2 times/week
Season total 1,489 gal / 100 sq ft
Drought risk

Water stress score is 6/10 โ€” 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 โ€” 3.2" 0" โ„๏ธ Dormant
Feb 4.3" 3.3" 1" ๐Ÿ’ง Light watering
Mar 4.3" 3.6" 0.7" ๐Ÿ’ง Light watering
Apr 4.3" 2.7" 1.6" ๐Ÿ’ง Light watering
May 4.3" 4.3" 0" โœ… Rainfall sufficient
Jun 4.3" 8" 0" โœ… Rainfall sufficient
Jul 4.3" 8.7" 0" โœ… Rainfall sufficient
Aug 4.3" 8.5" 0" โœ… Rainfall sufficient
Sep 4.3" 7.6" 0" โœ… Rainfall sufficient
Oct 4.3" 6.1" 0" โœ… Rainfall sufficient
Nov 4.3" 2.6" 1.7" ๐Ÿ’ง Light watering
Dec 4.3" 2.5" 1.8" ๐Ÿ’ง Light watering

Water needs are for active growing months only (Febโ€“Dec in Sumter 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 ~1,650 GDD — county provides 6,688 GDD Excellent fit

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

Fennel (herb) Planting Calendar

Activity When Date Range
Start Indoors January 9 Jan 9 โ€“ Jan 23
Transplant Outdoors January 30 Jan 30 โ€“ Feb 13
Direct Sow January 16 Jan 16 โ€“ Feb 6
Harvest April 3 Apr 3 โ€“ Jun 12
Fall Sowing October 11 Oct 11 โ€“ Oct 25

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 โ€”
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: acceptable

๐Ÿ—บ๏ธ USDA Zone

Zone 9a

๐Ÿ“† Growing Season

303 days in Sumter County

Growing Tips for Fennel (herb) in Sumter County

Direct sow Fennel (herb) outdoors after February 06 in Sumter County when soil has warmed and frost danger has passed.

Sandy soil in Sumter 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 96ยฐF in Sumter 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 Sumter County, FL?

Sumter County is in Zone 9a with an average last frost of February 6. Plan your Fennel (herb) planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Sumter County, FL?

Sumter County, Florida is in USDA Hardiness Zone 9a. The average last spring frost is February 6 and first fall frost is December 6.

๐ŸŒฑ

Plan Your Garden with Confidence

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

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