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When to Plant Basil in Flagler County, FL

Flagler County, Florida Zone 9b May

Top priorities for Flagler County, Florida gardeners in May

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

Avg. last frost February 5
Avg. first frost December 17
Soil temp (4") 77°F
Watering Moderate
Pest pressure High
Daylight 13.5 hrs
  1. Collect basil at their peak

    Morning harvests are best — cooler temperatures mean crisper produce and longer fridge life.

To set up a strong June, finish these tasks
  • First harvests: basil

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Basil is a fragrant warm-season herb essential to Italian and Thai cuisines. It comes in many varieties including sweet, Thai, purple, and lemon types.

Flagler County, Florida is in USDA Zone 9b. 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 99°F, so Basil may need afternoon shade and extra watering during peak heat. Sandy soil warms quickly in spring — great for early planting — but Basil will need more frequent watering and organic matter to retain nutrients. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Basil root diseases.

Flagler County, FL (Zone 9b) Year-round
315 days
Last Spring Frost February 5
315 growing days
First Fall Frost December 17
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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 11 Transplant: Jan 29 🍅 Harvest: Mar 26 – May 28
Recommended (50%) ✓ Fits season (189 days to spare)
Start indoors: Dec 25 Transplant: Feb 12 🍅 Harvest: Apr 9 – Jun 11
Safe Start (90%) ✓ Fits season (175 days to spare)
Start indoors: Jan 17 Transplant: Mar 7 🍅 Harvest: May 2 – 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 Basil's growing requirements.

Soil pH

Your soil pH (5.1–5.7) is more acidic than Basil prefers (6.0–7.0). Add garden lime to raise pH.

Soil Texture

Sandy soil in Flagler County warms quickly in spring but drains fast. Basil will need more frequent watering and regular compost additions to retain nutrients.

Drainage

Drainage is adequate for Basil.

Organic Matter

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

How to Plant Basil

0.5"
Planting Depth
8"
Between Plants
12"
Between Rows

Succession Planting Basil

7
successive plantings in your 315-day season

Sow every 5.7 weeks. Last sowing by Oct 03 to harvest before frost.

Plant Water Budget

Plant needs
0.6″/week
Rainfall provides
0.7″/week
You supply
0.1″/week
Watering frequency Only during dry spells
Season total 168 gal / 100 sq ft

Monthly Watering Guide for Basil

Basil 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 Basil Needs Rainfall You Supplement Action
Jan 2.7" 0" ❄️ Dormant
Feb 2.6" 2.5" 0.1" 💧 Light watering
Mar 2.6" 3" 0" ✅ Rainfall sufficient
Apr 2.6" 2.2" 0.4" 💧 Light watering
May 2.6" 3.7" 0" ✅ Rainfall sufficient
Jun 2.6" 8.8" 0" ✅ Rainfall sufficient
Jul 2.6" 7.7" 0" ✅ Rainfall sufficient
Aug 2.6" 7.4" 0" ✅ Rainfall sufficient
Sep 2.6" 6.9" 0" ✅ Rainfall sufficient
Oct 2.6" 4.7" 0" ✅ Rainfall sufficient
Nov 2.6" 2" 0.6" 💧 Light watering
Dec 2.6" 2.5" 0.1" 💧 Light watering

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

Basil 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.

Basil needs ~1,516 GDD — county provides 7,663 GDD Excellent fit

Basil Planting Timeline — Flagler County, FL

Basil Planting Calendar

Activity When Date Range
Start Indoors December 25 Dec 25 – Jan 8
Transplant Outdoors February 12 Feb 12 – Feb 26
Direct Sow February 12 Feb 12 – Mar 5
Harvest April 9 Apr 9 – Jun 11

Plant 0.5" deep · 8" apart · Rows 12" apart

Month-by-Month Timeline

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

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

0.6"/week · Only during dry spells

📅 Days to Maturity

50–75 days

🧪 Soil pH

Needs 6–7 · Your soil: too_acidic

🗺️ USDA Zone

Zone 9b

📆 Growing Season

315 days in Flagler County

Growing Tips for Basil in Flagler County

Direct sow Basil outdoors after February 05 in Flagler County when soil has warmed and frost danger has passed.

Sandy soil in Flagler County dries quickly — mulch Basil 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 Flagler County, provide afternoon shade for Basil and water deeply in the morning.

General growing tips

Start seeds indoors or direct sow after last frost. Pinch flower buds to extend leaf production. Harvest leaves from the top down, cutting just above a leaf pair.

Recommended Basil Varieties for Flagler County

Downy mildew-resistant basil for your humid climate

Prospera (DM-resistant) Amazel Eleonora

Companion Planting

Good Companions

Avoid Planting Near

  • Rue
  • Sage

Check more plant combinations with our Companion Planting Checker →

🌾 Save Your Own Basil Seeds
Life Cycle Annual
Pollination Self-Pollinating
How to Collect Let flower spikes dry brown on the plant.
Storage Store airtight; viable 5 years at 35°F, under 45% humidity.

Isolate 150 ft between varieties. Different basil species can cross.

Frequently Asked Questions

When should I plant Basil in Flagler County, FL?

Flagler County is in Zone 9b with an average last frost of February 5. Plan your Basil planting based on this frost date — see the calendar above for exact timing.

What planting zone is Flagler County, FL?

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

🌱

Your Flagler County Garden Planner — Free

A 24-page printable planner built for Flagler 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.

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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 Flagler 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.