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When to plant Thai Basil in Mapleton, KS

Mapleton gardeners should plant Thai Basil between April 15 and May 6 in spring. With Mapleton's Zone 7a climate (last frost April 8), Thai Basil needs 50–75 days to mature — plant by August 11 for a full harvest.

When to Plant Thai Basil in Mapleton, KS

Bourbon County, Kansas Zone 7a August

Your August game plan for Bourbon County, Kansas

If you only do a handful of things in the garden this August, make it these. They're sequenced around your zone's frost timing.

Avg. last frost April 8
Avg. first frost October 25
Soil temp (4") 84°F
Watering Moderate
Pest pressure High
Daylight 13.5 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.

Mapleton, Kansas is in USDA Zone 7a. The average last spring frost is April 8 and the first fall frost is October 25, giving you a growing season of approximately 200 days.

At an elevation of 438 feet, Bourbon County receives approximately 26 inches of rainfall annually with predominantly loam soil. Summer highs average 85°F, providing good warmth for Thai Basil during the growing season.

Mapleton, KS (Zone 7a) Long season
200 days
Last Spring Frost April 8
200 growing days
First Fall Frost October 25

Mapleton Soil Profile

Soil Type

Loam

Soil pH

6.2-7.2

Drainage

Well Drained

Thai Basil Planting Risk Windows

Early Start (70% safe) ✓ Fits season (67 days to spare)
Start indoors: Feb 12 Transplant: Apr 16 🍅 Harvest: Jun 11 – Aug 13
Recommended (50%) ✓ Fits season (67 days to spare)
Start indoors: Feb 18 Transplant: Apr 22 🍅 Harvest: Jun 17 – Aug 19
Safe Start (90%) ✓ Fits season (65 days to spare)
Start indoors: Mar 3 Transplant: May 5 🍅 Harvest: Jun 30 – Sep 1

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 Mapleton

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

Soil pH

Your soil pH (6.2–7.2) overlaps with Thai Basil's range (6.0–7.0), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is moderate (3.8%). 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

4
successive plantings in your 200-day season

Sow every 5.7 weeks. Last sowing by Aug 11 to harvest before frost.

Thai Basil Water Budget

Plant needs
1.0″/week
Rainfall provides
0.6″/week
You supply
0.5″/week
Watering frequency 1-2 times/week
Season total 808 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 0.6" 0" ❄️ Dormant
Feb 0.8" 0" ❄️ Dormant
Mar 1.8" 0" ❄️ Dormant
Apr 4.3" 2.7" 1.6" 💧 Light watering
May 4.3" 4.2" 0.1" 💧 Light watering
Jun 4.3" 3.8" 0.5" 💧 Light watering
Jul 4.3" 3.2" 1.1" 💧 Light watering
Aug 4.3" 3.3" 1" 💧 Light watering
Sep 4.3" 2.4" 1.9" 💧 Light watering
Oct 4.3" 1.8" 2.5" 🚿 Regular watering
Nov 0.8" 0" ❄️ Dormant
Dec 0.6" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Bourbon 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 ~859 GDD — county provides 2,750 GDD Excellent fit

Thai Basil Planting Timeline — Mapleton, KS

Thai Basil Planting Calendar

Activity When Date Range
Start Indoors February 18 Feb 18 – Mar 4
Transplant Outdoors April 22 Apr 22 – May 6
Direct Sow April 15 Apr 15 – May 6
Harvest June 17 Jun 17 – Aug 19

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · 1-2 times/week

📅 Days to Maturity

50–75 days

🧪 Soil pH

Needs 6–7 · Your soil: acceptable

🗺️ USDA Zone

Zone 7a

📆 Growing Season

200 days in Bourbon County

Growing Tips for Thai Basil in Mapleton

Direct sow Thai Basil outdoors after April 08 in Bourbon 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 Mapleton, KS?

In Mapleton, KS, plant Thai Basil after the last frost (around April 8) and before the first frost (around October 25). Best results when soil holds above 50°F.

What growing zone is Mapleton, KS for Thai Basil?

Mapleton sits in USDA Zone 7a. Thai Basil grows reliably in zones 4a through 11b, so it's a good fit here.

Can Thai Basil grow in Mapleton's climate?

Yes — Thai Basil grows well in Mapleton's temperate climate. Mapleton averages a 200-day frost-free season, with last frost around April 8 and first frost around October 25.

🌱

Your Bourbon County Garden Planner — Free

A 22-page printable planner built for Bourbon 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 Bourbon County, KS. Local conditions may vary. Last updated: August 2026.