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When to plant Thai Basil in Kossuth County County,

Aim to plant Thai Basil in Kossuth County County on or after May 4; the window stays open through May 25. Kossuth County County's 162-day frost-free season gives you a single solid spring crop with a brief fall option.

When to Plant Thai Basil in Kossuth County, IA

Kossuth County, Iowa Zone 5a June

Your June game plan for Kossuth County, Iowa

A quick June briefing for Kossuth County, Iowa gardeners — what's urgent, what's next, and what can wait.

Avg. last frost April 27
Avg. first frost October 6
Soil temp (4") 66°F
Watering Low
Pest pressure High
Daylight 15.2 hrs
  1. Get thai basil seeds going inside

    Bottom-water once the first true leaves appear — it keeps stems dry and knocks back damping-off.

July will be here before you know it — start on
  • First harvests: 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.

Kossuth County, Iowa is in USDA Zone 5a. The average last spring frost is April 27 and the first fall frost is October 6, giving you a growing season of approximately 162 days.

At an elevation of 1,213 feet, Kossuth County receives approximately 36.5 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.

Kossuth County, IA (Zone 5a) Moderate season
162 days
Last Spring Frost April 27
162 growing days
First Fall Frost October 6

Kossuth County Soil Profile

Soil Type

Silt Loam

Soil pH

6.2-7

Drainage

Well Drained

Thai Basil Planting Risk Windows

Early Start (70% safe) ✓ Fits season (31 days to spare)
Start indoors: Mar 3 Transplant: May 5 🍅 Harvest: Jun 30 – Sep 1
Recommended (50%) ✓ Fits season (29 days to spare)
Start indoors: Mar 9 Transplant: May 11 🍅 Harvest: Jul 6 – Sep 7
Safe Start (90%) ✓ Fits season (31 days to spare)
Start indoors: Mar 23 Transplant: May 25 🍅 Harvest: Jul 20 – Sep 21

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 Kossuth County

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

Soil pH

Your soil pH (6.2–7.0) is within Thai Basil's preferred range (6.0–7.0).

Soil Texture

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

Organic Matter

Organic matter is excellent (4.9%) — 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 162-day season

Sow every 5.7 weeks. Last sowing by Jul 23 to harvest before frost.

Thai Basil Water Budget

Plant needs
1.0″/week
Rainfall provides
1.0″/week
You supply
0.1″/week
Watering frequency Only during dry spells
Season total 77 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 1.7" 0" ❄️ Dormant
Feb 1.4" 0" ❄️ Dormant
Mar 2.4" 0" ❄️ Dormant
Apr 4.3" 3.8" 0.5" 💧 Light watering
May 4.3" 3.7" 0.6" 💧 Light watering
Jun 4.3" 5.1" 0" ✅ Rainfall sufficient
Jul 4.3" 4.3" 0" ✅ Rainfall sufficient
Aug 4.3" 3.7" 0.6" 💧 Light watering
Sep 4.3" 2.9" 1.4" 💧 Light watering
Oct 4.3" 3.2" 1.1" 💧 Light watering
Nov 2.5" 0" ❄️ Dormant
Dec 1.8" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Kossuth 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 1,620 GDD Excellent fit

Thai Basil Planting Timeline — Kossuth County, IA

Thai Basil Planting Calendar

Activity When Date Range
Start Indoors March 9 Mar 9 – Mar 23
Transplant Outdoors May 11 May 11 – May 25
Direct Sow May 4 May 4 – May 25
Harvest July 6 Jul 6 – Sep 7

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · Only during dry spells

📅 Days to Maturity

50–75 days

🧪 Soil pH

Needs 6–7 · Your soil: ideal

🗺️ USDA Zone

Zone 5a

📆 Growing Season

162 days in Kossuth County

Growing Tips for Thai Basil in Kossuth County

Direct sow Thai Basil outdoors after April 27 in Kossuth 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 Kossuth County, IA?

Kossuth County is in Zone 5a with an average last frost of April 27. Plan your Thai Basil planting based on this frost date — see the calendar above for exact timing.

What planting zone is Kossuth County, IA?

Kossuth County, Iowa is in USDA Hardiness Zone 5a. The average last spring frost is April 27 and first fall frost is October 6.

When should I plant Thai Basil in Kossuth County County, ?

In Kossuth County County, , plant Thai Basil after the last frost (around April 27) and before the first frost (around October 6). Best results when soil holds above 50°F.

What growing zone is Kossuth County County, for Thai Basil?

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

Can Thai Basil grow in Kossuth County County's climate?

Yes — Thai Basil grows well in Kossuth County County's temperate climate. Kossuth County County averages a 162-day frost-free season, with last frost around April 27 and first frost around October 6.

🌱

Your Kossuth County Garden Planner — Free

A 22-page printable planner built for Kossuth County (Zone 5a). 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 Kossuth County, IA. Local conditions may vary. Last updated: June 2026.

Sources & credits

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