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When to Plant Thai Basil in Valdez-Cordova, AK

Valdez-Cordova, Alaska Zone 5b May

Top priorities for Valdez-Cordova, Alaska gardeners in May

Your Valdez-Cordova, Alaska garden is entering a new phase. Here's what's on the schedule for May and why each task matters now.

Avg. last frost May 12
Avg. first frost October 5
Soil temp (4") 47°F
Watering High
Pest pressure Low
Daylight 17.1 hrs
  1. Time to transplant thai basil

    Your last frost (May 12) has passed. These warm-season crops can handle outdoor soil now.

  2. Plant thai basil from seed, right in the garden

    Your soil is 47°F — warm enough for these to germinate without babying.

June will be here before you know it — start on
  • 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.

Valdez-Cordova, Alaska is in USDA Zone 5b. The average last spring frost is May 12 and the first fall frost is October 5, giving you a growing season of approximately 146 days.

At an elevation of 2,888 feet, Valdez-Cordova receives approximately 38.3 inches of rainfall annually with predominantly silt loam soil. Summer highs average 66°F, so choose short-season varieties of Thai Basil to ensure they mature before fall.

Valdez-Cordova, AK (Zone 5b) Short season
146 days
Last Spring Frost May 12
146 growing days
First Fall Frost October 5
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Valdez-Cordova Soil Profile

Soil Type

Silt Loam

Soil pH

5-6.8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (7 days to spare)
Start indoors: Mar 12 Transplant: May 14 🍅 Harvest: Jul 9 – Sep 10
Recommended (50%) ✓ Fits season (13 days to spare)
Start indoors: Mar 24 Transplant: May 26 🍅 Harvest: Jul 21 – Sep 22
Safe Start (90%) ✓ Fits season (14 days to spare)
Start indoors: Apr 16 Transplant: Jun 18 🍅 Harvest: Aug 13 – Oct 15

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 Valdez-Cordova

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

Soil pH

Your soil pH (5.0–6.8) is more acidic than Thai Basil prefers (6.0–7.0). Add garden lime to raise pH.

Soil Texture

The silt loam soil in Valdez-Cordova 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 excellent (6.2%) — Thai Basil will thrive.

How to Plant Thai Basil

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

Succession Planting Thai Basil

3
successive plantings in your 146-day season

Sow every 5.7 weeks. Last sowing by Jul 22 to harvest before frost.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
1.1″/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 1.9" 0" ❄️ Dormant
Feb 1.8" 0" ❄️ Dormant
Mar 1.5" 0" ❄️ Dormant
Apr 1.2" 0" ❄️ Dormant
May 4.3" 1.5" 2.8" 🚿 Regular watering
Jun 4.3" 2.9" 1.4" 💧 Light watering
Jul 4.3" 5.3" 0" ✅ Rainfall sufficient
Aug 4.3" 5.5" 0" ✅ Rainfall sufficient
Sep 4.3" 6" 0" ✅ Rainfall sufficient
Oct 4.3" 5.3" 0" ✅ Rainfall sufficient
Nov 2.9" 0" ❄️ Dormant
Dec 2.4" 0" ❄️ Dormant

Water needs are for active growing months only (May–Oct in Valdez-Cordova). 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 ~0 GDD — county provides 0 GDD May not mature

Thai Basil Planting Timeline — Valdez-Cordova, AK

Thai Basil Planting Calendar

Activity When Date Range
Start Indoors March 24 Mar 24 – Apr 7
Transplant Outdoors May 26 May 26 – Jun 9
Direct Sow May 19 May 19 – Jun 9
Harvest July 21 Jul 21 – Sep 22

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
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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: too_acidic

🗺️ USDA Zone

Zone 5b

📆 Growing Season

146 days in Valdez-Cordova

Growing Tips for Thai Basil in Valdez-Cordova

Direct sow Thai Basil outdoors after May 12 in Valdez-Cordova 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 Valdez-Cordova, AK?

Valdez-Cordova is in Zone 5b with an average last frost of May 12. Plan your Thai Basil planting based on this frost date — see the calendar above for exact timing.

What planting zone is Valdez-Cordova, AK?

Valdez-Cordova, Alaska is in USDA Hardiness Zone 5b. The average last spring frost is May 12 and first fall frost is October 5.

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Your Valdez-Cordova Garden Planner — Free

A 24-page printable planner built for Valdez-Cordova (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 Valdez-Cordova, AK. 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.