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When to Plant Thai Basil in Prince George's County, MD

Prince George's County, Maryland Zone 7a April

Your April planting checklist for Prince George's County, Maryland

A quick April briefing for Prince George's County, Maryland gardeners — what's urgent, what's next, and what can wait.

Avg. last frost April 1
Avg. first frost November 10
Soil temp (4") 58°F
Watering Moderate
Pest pressure Moderate
Daylight 13 hrs
  1. Transplant thai basil outside

    Harden off for 7 days — a little more sun each day — before planting. That's the difference between a seedling that thrives and one that stalls.

  2. Direct-sow thai basil

    Rake a smooth bed, make a shallow furrow, drop seeds at the spacing on the packet, water gently, walk away.

A few tasks this April that'll pay off in May
  • Starting indoors: thai basil

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Thai basil has a distinctive anise-licorice flavor with sturdy purple stems and small leaves. It is essential in Thai, Vietnamese, and other Southeast Asian cuisines.

Prince George's County, Maryland is in USDA Zone 7a. The average last spring frost is April 1 and the first fall frost is November 10, giving you a growing season of approximately 223 days.

At an elevation of 322 feet, Prince George's County receives approximately 39.2 inches of rainfall annually with predominantly silt loam soil. Summer highs average 90°F, providing good warmth for Thai Basil during the growing season.

Prince George's County, MD (Zone 7a) Long season
223 days
Last Spring Frost April 1
223 growing days
First Fall Frost November 10
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Prince George's County Soil Profile

Soil Type

Silt Loam

Soil pH

5.3-6.9

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (89 days to spare)
Start indoors: Feb 5 Transplant: Apr 9 🍅 Harvest: Jun 4 – Aug 6
Recommended (50%) ✓ Fits season (90 days to spare)
Start indoors: Feb 11 Transplant: Apr 15 🍅 Harvest: Jun 10 – Aug 12
Safe Start (90%) ✓ Fits season (103 days to spare)
Start indoors: Feb 27 Transplant: May 1 🍅 Harvest: Jun 26 – Aug 28

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 Prince George's County

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

Soil pH

Your soil pH (5.3–6.9) overlaps with Thai Basil's range (6.0–7.0), though not a perfect match.

Soil Texture

The silt loam soil in Prince George's County is excellent for Thai Basil — good drainage, moisture retention, and nutrient holding capacity.

Drainage

Drainage is adequate for Thai Basil.

Organic Matter

Organic matter is moderate (3.0%). Annual compost additions will help Thai Basil.

How to Plant Thai Basil

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

Succession Planting Thai Basil

5
successive plantings in your 223-day season

Sow every 5.7 weeks. Last sowing by Aug 27 to harvest before frost.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.7″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft

Monthly Watering Guide for Thai Basil

Thai Basil needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.

Month Thai Basil Needs Rainfall You Supplement Action
Jan 2.4" 0" ❄️ Dormant
Feb 2.5" 0" ❄️ Dormant
Mar 3.4" 0" ❄️ Dormant
Apr 4.3" 3.7" 0.6" 💧 Light watering
May 4.3" 3.6" 0.7" 💧 Light watering
Jun 4.3" 3.6" 0.7" 💧 Light watering
Jul 4.3" 3.3" 1" 💧 Light watering
Aug 4.3" 3.4" 0.9" 💧 Light watering
Sep 4.3" 3.6" 0.7" 💧 Light watering
Oct 4.3" 3.5" 0.8" 💧 Light watering
Nov 4.3" 3.2" 1.1" 💧 Light watering
Dec 3" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Nov in Prince George's County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.

Thai 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.

Thai Basil needs ~1,094 GDD — county provides 3,902 GDD Excellent fit

Thai Basil Planting Timeline — Prince George's County, MD

Thai Basil Planting Calendar

Activity When Date Range
Start Indoors February 11 Feb 11 – Feb 25
Transplant Outdoors April 15 Apr 15 – Apr 29
Direct Sow April 8 Apr 8 – Apr 29
Harvest June 10 Jun 10 – Aug 12

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

Month-by-Month Timeline

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

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · Natural rainfall sufficient

📅 Days to Maturity

50–75 days

🧪 Soil pH

Needs 6–7 · Your soil: acceptable

🗺️ USDA Zone

Zone 7a

📆 Growing Season

223 days in Prince George's County

Growing Tips for Thai Basil in Prince George's County

Direct sow Thai Basil outdoors after April 01 in Prince George's County when soil has warmed and frost danger has passed.

General growing tips

Start seeds indoors or direct sow after last frost. Thai basil holds up better to heat in cooking than sweet basil. Pinch flowers to prolong leaf production.

Companion Planting

Good Companions

Avoid Planting Near

  • Rue
  • Sage

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Thai Basil in Prince George's County, MD?

Prince George's County is in Zone 7a with an average last frost of April 1. Plan your Thai Basil planting based on this frost date — see the calendar above for exact timing.

What planting zone is Prince George's County, MD?

Prince George's County, Maryland is in USDA Hardiness Zone 7a. The average last spring frost is April 1 and first fall frost is November 10.

🌱

Your Prince George's County Garden Planner — Free

A 24-page printable planner built for Prince George's County (Zone 7a). 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 Prince George's County, MD. Local conditions may vary. Last updated: April 2026.

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.