Blog

When to Plant Fennel in Putnam County, FL

Putnam County, Florida Zone 9b May

Your May gardening checklist

Your Putnam 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 February 9
Avg. first frost December 2
Soil temp (4") 76°F
Watering Moderate
Pest pressure High
Daylight 13.5 hrs
  1. Harvest fennel as they ripen

    Taste as you pick. The first ripe produce is the best feedback loop you'll get all season.

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

Instant PDF download. No spam, unsubscribe any time.

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.

Putnam County, Florida is in USDA Zone 9b. The average last spring frost is February 9 and the first fall frost is December 2, giving you a growing season of approximately 296 days.

At an elevation of 278 feet, Putnam County receives approximately 57.5 inches of rainfall annually with predominantly sand soil. Summer highs average 95°F, so Fennel may need afternoon shade and extra watering during peak heat. 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.

Putnam County, FL (Zone 9b) Year-round
296 days
Last Spring Frost February 9
296 growing days
First Fall Frost December 2
Share this guide:

Putnam County Soil Profile

Soil Type

Sand

Soil pH

4.9-6.2

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (192 days to spare)
Start indoors: Dec 14 Transplant: Feb 1 🍅 Harvest: Apr 5 – May 17
Recommended (50%) ✓ Fits season (184 days to spare)
Start indoors: Dec 29 Transplant: Feb 16 🍅 Harvest: Apr 20 – Jun 1
Safe Start (90%) ✓ Fits season (185 days to spare)
Start indoors: Jan 21 Transplant: Mar 11 🍅 Harvest: May 13 – Jun 24

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 Putnam County

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

Soil pH

Your soil pH (4.9–6.2) overlaps with Fennel's range (5.5–7.0), though not a perfect match.

Soil Texture

Sandy soil in Putnam 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 (1.4%). 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 296-day season

Sow every 6.9 weeks. Last sowing by Sep 03 to harvest before frost.

Plant Water Budget

Plant needs
0.6″/week
Rainfall provides
0.8″/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 2.4" 0" ❄️ Dormant
Feb 2.6" 2.6" 0" ✅ Rainfall sufficient
Mar 2.6" 3.5" 0" ✅ Rainfall sufficient
Apr 2.6" 2.3" 0.3" 💧 Light watering
May 2.6" 3.3" 0" ✅ Rainfall sufficient
Jun 2.6" 7.9" 0" ✅ Rainfall sufficient
Jul 2.6" 9.4" 0" ✅ Rainfall sufficient
Aug 2.6" 8.7" 0" ✅ Rainfall sufficient
Sep 2.6" 7.4" 0" ✅ Rainfall sufficient
Oct 2.6" 5.3" 0" ✅ Rainfall sufficient
Nov 2.6" 2.2" 0.4" 💧 Light watering
Dec 2.6" 2.6" 0" ✅ Rainfall sufficient

Water needs are for active growing months only (Feb–Dec in Putnam 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 ~1,594 GDD — county provides 6,311 GDD Excellent fit

Fennel Planting Timeline — Putnam County, FL

Fennel Planting Calendar

Activity When Date Range
Start Indoors December 29 Dec 29 – Jan 12
Transplant Outdoors February 16 Feb 16 – Mar 2
Direct Sow February 9 Feb 9 – Mar 2
Harvest April 20 Apr 20 – Jun 1

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

Month-by-Month Timeline

MonthActivities
January Start Indoors
February Transplant Outdoors Direct Sow
March Transplant Outdoors Direct Sow
April Harvest
May Harvest
June Harvest
July
August
September
October
November
December Start Indoors
Share this guide:

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: acceptable

🗺️ USDA Zone

Zone 9b

📆 Growing Season

296 days in Putnam County

Growing Tips for Fennel in Putnam County

Direct sow Fennel outdoors after February 09 in Putnam County when soil has warmed and frost danger has passed.

Sandy soil in Putnam 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 Putnam County, FL?

Putnam County is in Zone 9b with an average last frost of February 9. Plan your Fennel planting based on this frost date — see the calendar above for exact timing.

What planting zone is Putnam County, FL?

Putnam County, Florida is in USDA Hardiness Zone 9b. The average last spring frost is February 9 and first fall frost is December 2.

🌱

Your Putnam County Garden Planner — Free

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

Instant PDF download. No spam, unsubscribe any time.

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Putnam 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.