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When to Plant Basil in Monroe County, FL

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.

Monroe County, Florida is in USDA Zone 11a. The average last spring frost is January 22 and the first fall frost is April 15, giving you a growing season of approximately 83 days.

At an elevation of 169 feet, Monroe County receives approximately 55.6 inches of rainfall annually with predominantly sand soil. Summer highs average 93ยฐF, providing good warmth for Basil during the growing season. Sandy soil warms quickly in spring โ€” great for early planting โ€” 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.

Monroe County, FL (Zone 11a) Very short season
83 days
Last Spring Frost January 22
83 growing days
First Fall Frost April 15

Monroe County Soil Profile

Soil Type

Sand

Soil pH

4.8-5.7

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (145 days to spare)
Start indoors: Dec 6 Transplant: Jan 24 🍅 Harvest: Mar 21 – May 23
Recommended (50%) ✓ Fits season (140 days to spare)
Start indoors: Dec 11 Transplant: Jan 29 🍅 Harvest: Mar 26 – May 28
Safe Start (90%) ✓ Fits season (87 days to spare)
Start indoors: Feb 2 Transplant: Mar 23 🍅 Harvest: May 18 – Jul 20

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 Monroe County

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

Soil pH

Your soil pH (4.8โ€“5.7) is more acidic than Basil prefers (6.0โ€“7.0). Add garden lime to raise pH.

Soil Texture

Sandy soil in Monroe 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 (1.3%). Add 2-3 inches of compost before planting Basil.

How to Plant Basil

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

Plant Water Budget

Plant needs
0.6″/week
Rainfall provides
0.6″/week
You supply
0.1″/week
Watering frequency Only during dry spells
Season total 456 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 2.6" 2.3" 0.3" ๐Ÿ’ง Light watering
Feb 2.6" 2.7" 0" โœ… Rainfall sufficient
Mar 2.6" 3.8" 0" โœ… Rainfall sufficient
Apr 2.6" 2.5" 0.1" ๐Ÿ’ง Light watering
May 2.6" 3.2" 0" โœ… Rainfall sufficient
Jun 2.6" 7.1" 0" โœ… Rainfall sufficient
Jul 2.6" 8.2" 0" โœ… Rainfall sufficient
Aug 2.6" 8.7" 0" โœ… Rainfall sufficient
Sep 2.6" 7.7" 0" โœ… Rainfall sufficient
Oct 2.6" 4.8" 0" โœ… Rainfall sufficient
Nov โ€” 2.2" 0" โ„๏ธ Dormant
Dec โ€” 2.5" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Janโ€“Oct in Monroe County). Supplement amounts are based on average rainfall โ€” 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" 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.

Basil needs ~1,234 GDD — county provides 7,208 GDD Excellent fit

Basil Planting Timeline โ€” Monroe County, FL

Basil Planting Calendar

Activity When Date Range
Start Indoors December 11 Dec 11 โ€“ Dec 25
Transplant Outdoors January 29 Jan 29 โ€“ Feb 12
Direct Sow January 29 Jan 29 โ€“ Feb 19
Harvest March 26 Mar 26 โ€“ May 28

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

Month-by-Month Timeline

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

Growing Conditions

โ˜€๏ธ Sun

Full Sun (6-8+ hours)

๐Ÿ’ง Water

0.6"/week ยท Only during dry spells

๐Ÿ“… Days to Maturity

50โ€“75 days

๐Ÿงช Soil pH

Needs 6โ€“7 ยท Your soil: too_acidic

๐Ÿ—บ๏ธ USDA Zone

Zone 11a

๐Ÿ“† Growing Season

83 days in Monroe County

Growing Tips for Basil in Monroe County

Direct sow Basil outdoors after January 22 in Monroe County when soil has warmed and frost danger has passed.

Sandy soil in Monroe County dries quickly โ€” mulch Basil with 2-3 inches of straw and water deeply 2-3 times per week rather than lightly every day.

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 Monroe 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 →

๐ŸŒพ 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 35ยฐF, under 45% humidity.

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

Frequently Asked Questions

When should I plant Basil in Monroe County, FL?

Monroe County is in Zone 11a with an average last frost of January 22. Plan your Basil planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Monroe County, FL?

Monroe County, Florida is in USDA Hardiness Zone 11a. The average last spring frost is January 22 and first fall frost is .

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Monroe County gardeners in Zone 11a 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 Monroe County, FL. Local conditions may vary. Last updated: April 2026.