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When to Plant Basil in Mobile County, AL

Mobile County, Alabama Zone 9a May

This month in Mobile County, Alabama

Your Mobile County, Alabama garden is entering a new phase. Here's what's on the schedule for May and why each task matters now.

Avg. last frost March 3
Avg. first frost November 24
Soil temp (4") 71°F
Watering Moderate
Pest pressure High
Daylight 13.6 hrs
  1. It's harvest week for basil

    Don't tug. Use scissors or pruners for clean cuts — torn stems invite disease.

Before June arrives, get these ready
  • 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.

Mobile County, Alabama is in USDA Zone 9a. The average last spring frost is March 3 and the first fall frost is November 24, giving you a growing season of approximately 266 days.

At an elevation of 101 feet, Mobile County receives approximately 48.3 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 97°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.

Mobile County, AL (Zone 9a) Long season
266 days
Last Spring Frost March 3
266 growing days
First Fall Frost November 24
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Mobile County Soil Profile

Soil Type

Sandy Loam

Soil pH

4.8-6.1

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (145 days to spare)
Start indoors: Jan 8 Transplant: Feb 26 🍅 Harvest: Apr 23 – Jun 25
Recommended (50%) ✓ Fits season (140 days to spare)
Start indoors: Jan 20 Transplant: Mar 10 🍅 Harvest: May 5 – Jul 7
Safe Start (90%) ✓ Fits season (140 days to spare)
Start indoors: Feb 6 Transplant: Mar 27 🍅 Harvest: May 22 – Jul 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 Mobile County

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

Soil pH

Your soil pH (4.8–6.1) is more acidic than Basil prefers (6.0–7.0). Add garden lime to raise pH.

Soil Texture

Sandy soil in Mobile 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 moderate (2.2%). Annual compost additions will help Basil.

How to Plant Basil

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

Succession Planting Basil

6
successive plantings in your 266-day season

Sow every 5.7 weeks. Last sowing by Sep 10 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

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 3.7" 0" ❄️ Dormant
Feb 3.5" 0" ❄️ Dormant
Mar 2.6" 4.9" 0" ✅ Rainfall sufficient
Apr 2.6" 3.7" 0" ✅ Rainfall sufficient
May 2.6" 3.5" 0" ✅ Rainfall sufficient
Jun 2.6" 4" 0" ✅ Rainfall sufficient
Jul 2.6" 5.5" 0" ✅ Rainfall sufficient
Aug 2.6" 4.2" 0" ✅ Rainfall sufficient
Sep 2.6" 3.6" 0" ✅ Rainfall sufficient
Oct 2.6" 3.5" 0" ✅ Rainfall sufficient
Nov 2.6" 4.3" 0" ✅ Rainfall sufficient
Dec 4" 0" ❄️ Dormant

Water needs are for active growing months only (Mar–Nov in Mobile 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 ~1,422 GDD — county provides 6,051 GDD Excellent fit

Basil Planting Timeline — Mobile County, AL

Basil Planting Calendar

Activity When Date Range
Start Indoors January 20 Jan 20 – Feb 3
Transplant Outdoors March 10 Mar 10 – Mar 24
Direct Sow March 10 Mar 10 – Mar 31
Harvest May 5 May 5 – Jul 7

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

Month-by-Month Timeline

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

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

0.6"/week · Natural rainfall sufficient

📅 Days to Maturity

50–75 days

🧪 Soil pH

Needs 6–7 · Your soil: too_acidic

🗺️ USDA Zone

Zone 9a

📆 Growing Season

266 days in Mobile County

Growing Tips for Basil in Mobile County

Direct sow Basil outdoors after March 03 in Mobile County when soil has warmed and frost danger has passed.

Sandy soil in Mobile 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 97°F in Mobile 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.

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 Mobile County, AL?

Mobile County is in Zone 9a with an average last frost of March 3. Plan your Basil planting based on this frost date — see the calendar above for exact timing.

What planting zone is Mobile County, AL?

Mobile County, Alabama is in USDA Hardiness Zone 9a. The average last spring frost is March 3 and first fall frost is November 24.

🌱

Your Mobile County Garden Planner — Free

A 24-page printable planner built for Mobile County (Zone 9a). 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 Mobile County, AL. 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.