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When to plant Thai Basil in Danforth, ME

Spring Thai Basil in Danforth goes in May 16–June 6, once nighttime temps stop dipping near freezing.

When to Plant Thai Basil in Danforth, ME

Washington County, Maine Zone 5b July

Your July game plan for Washington County, Maine

Your garden in Washington County, Maine is working on a schedule, even when you're not. Here's where you should be this July.

Avg. last frost May 9
Avg. first frost October 7
Soil temp (4") 71°F
Watering Low
Pest pressure High
Daylight 15.1 hrs

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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.

Danforth, Maine is in USDA Zone 5b. The average last spring frost is May 9 and the first fall frost is October 7, giving you a growing season of approximately 151 days.

At an elevation of 1,184 feet, Washington County receives approximately 43.9 inches of rainfall annually with predominantly silt loam soil. Summer highs average 80°F, so choose short-season varieties of Thai Basil to ensure they mature before fall.

Danforth, ME (Zone 5b) Moderate season
151 days
Last Spring Frost May 9
151 growing days
First Fall Frost October 7

Danforth Soil Profile

Soil Type

Silt Loam

Soil pH

5-6.5

Drainage

Well Drained

Thai Basil Planting Risk Windows

Early Start (70% safe) ✓ Fits season (23 days to spare)
Start indoors: Mar 13 Transplant: May 15 🍅 Harvest: Jul 10 – Sep 11
Recommended (50%) ✓ Fits season (18 days to spare)
Start indoors: Mar 21 Transplant: May 23 🍅 Harvest: Jul 18 – Sep 19
Safe Start (90%) ✓ Fits season (25 days to spare)
Start indoors: Apr 8 Transplant: Jun 10 🍅 Harvest: Aug 5 – Oct 7

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 Danforth

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

Soil pH

Your soil pH (5.0–6.5) is more acidic than Thai Basil prefers (6.0–7.0). Add garden lime to raise pH.

Soil Texture

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

Organic Matter

Organic matter is moderate (3.7%). 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

3
successive plantings in your 151-day season

Sow every 5.7 weeks. Last sowing by Jul 24 to harvest before frost.

Thai Basil Water Budget

Plant needs
1.0″/week
Rainfall provides
1.2″/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 3.2" 0" ❄️ Dormant
Feb 3" 0" ❄️ Dormant
Mar 4.1" 0" ❄️ Dormant
Apr 3.5" 0" ❄️ Dormant
May 4.3" 3.5" 0.8" 💧 Light watering
Jun 4.3" 4.7" 0" ✅ Rainfall sufficient
Jul 4.3" 4.1" 0.2" 💧 Light watering
Aug 4.3" 4.1" 0.2" 💧 Light watering
Sep 4.3" 3.8" 0.5" 💧 Light watering
Oct 4.3" 3.4" 0.9" 💧 Light watering
Nov 3.4" 0" ❄️ Dormant
Dec 3.2" 0" ❄️ Dormant

Water needs are for active growing months only (May–Oct in Washington 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 ~625 GDD — county provides 1,510 GDD Excellent fit

Thai Basil Planting Timeline — Danforth, ME

Thai Basil Planting Calendar

Activity When Date Range
Start Indoors March 21 Mar 21 – Apr 4
Transplant Outdoors May 23 May 23 – Jun 6
Direct Sow May 16 May 16 – Jun 6
Harvest July 18 Jul 18 – Sep 19

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

Month-by-Month Timeline

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

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: too_acidic

🗺️ USDA Zone

Zone 5b

📆 Growing Season

151 days in Washington County

Growing Tips for Thai Basil in Danforth

Direct sow Thai Basil outdoors after May 09 in Washington 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 →

When should I plant Thai Basil in Danforth, ME?

In Danforth, ME, plant Thai Basil after the last frost (around May 9) and before the first frost (around October 7). Best results when soil holds above 50°F.

What growing zone is Danforth, ME for Thai Basil?

Danforth sits in USDA Zone 5b. Thai Basil grows reliably in zones 4a through 11b, so it's a good fit here.

Can Thai Basil grow in Danforth's climate?

Yes — Thai Basil grows well in Danforth's temperate climate. Danforth averages a 151-day frost-free season, with last frost around May 9 and first frost around October 7.

🌱

Your Washington County Garden Planner — Free

A 22-page printable planner built for Washington County (Zone 5b). 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 Washington County, ME. Local conditions may vary. Last updated: July 2026.