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When to Plant Shiso in Gibson County, IN

Gibson County, Indiana Zone 7a May

May to-do list for Gibson County, Indiana

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

Avg. last frost April 6
Avg. first frost October 28
Soil temp (4") 64°F
Watering Low
Pest pressure Low
Daylight 14.1 hrs
  1. Sow shiso in trays indoors

    Label every cell. You will absolutely forget which is which otherwise.

Looking ahead to June
  • First harvests: shiso

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Shiso (perilla) is a fragrant Japanese herb with large, ruffled leaves in green or purple varieties. It has a unique flavor combining mint, basil, and anise.

Gibson County, Indiana is in USDA Zone 7a. The average last spring frost is April 6 and the first fall frost is October 28, giving you a growing season of approximately 205 days.

At an elevation of 652 feet, Gibson County receives approximately 38.4 inches of rainfall annually with predominantly silt loam soil. Summer highs average 91°F, providing good warmth for Shiso during the growing season.

Gibson County, IN (Zone 7a) Long season
205 days
Last Spring Frost April 6
205 growing days
First Fall Frost October 28
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Gibson County Soil Profile

Soil Type

Silt Loam

Soil pH

6.2-7

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (79 days to spare)
Start indoors: Feb 9 Transplant: Apr 13 🍅 Harvest: Jun 8 – Aug 3
Recommended (50%) ✓ Fits season (79 days to spare)
Start indoors: Feb 16 Transplant: Apr 20 🍅 Harvest: Jun 15 – Aug 10
Safe Start (90%) ✓ Fits season (83 days to spare)
Start indoors: Mar 2 Transplant: May 4 🍅 Harvest: Jun 29 – Aug 24

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 Gibson County

How your county's soil matches Shiso's growing requirements.

Soil pH

Your soil pH (6.2–7.0) is within Shiso's preferred range (5.5–7.0).

Soil Texture

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

Organic Matter

Organic matter is excellent (4.4%) — Shiso will thrive.

How to Plant Shiso

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

Succession Planting Shiso

4
successive plantings in your 205-day season

Sow every 5.7 weeks. Last sowing by Aug 19 to harvest before frost.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.8″/week
You supply
0.2″/week
Watering frequency Only during dry spells
Season total 389 gal / 100 sq ft

Monthly Watering Guide for Shiso

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

Month Shiso Needs Rainfall You Supplement Action
Jan 1.7" 0" ❄️ Dormant
Feb 1.8" 0" ❄️ Dormant
Mar 2.3" 0" ❄️ Dormant
Apr 4.3" 3.5" 0.8" 💧 Light watering
May 4.3" 4.7" 0" ✅ Rainfall sufficient
Jun 4.3" 5.2" 0" ✅ Rainfall sufficient
Jul 4.3" 4.4" 0" ✅ Rainfall sufficient
Aug 4.3" 4" 0.3" 💧 Light watering
Sep 4.3" 3.2" 1.1" 💧 Light watering
Oct 4.3" 2.7" 1.6" 💧 Light watering
Nov 2.4" 0" ❄️ Dormant
Dec 2.3" 0" ❄️ Dormant

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

Shiso 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.

Shiso needs ~1,095 GDD — county provides 3,741 GDD Excellent fit

Shiso Planting Timeline — Gibson County, IN

Shiso Planting Calendar

Activity When Date Range
Start Indoors February 16 Feb 16 – Mar 2
Transplant Outdoors April 20 Apr 20 – May 4
Direct Sow April 13 Apr 13 – May 4
Harvest June 15 Jun 15 – Aug 10

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
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Growing Conditions

☀️ Sun

Partial Shade (3-6 hours)

💧 Water

1"/week · Only during dry spells

📅 Days to Maturity

50–70 days

🧪 Soil pH

Needs 5.5–7 · Your soil: ideal

🗺️ USDA Zone

Zone 7a

📆 Growing Season

205 days in Gibson County

Growing Tips for Shiso in Gibson County

Direct sow Shiso outdoors after April 06 in Gibson County when soil has warmed and frost danger has passed.

General growing tips

Direct sow after last frost or start indoors. Both green and red varieties are available. Pinch tips to encourage bushiness. Self-sows prolifically; deadhead to control.

Companion Planting

Good Companions

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Shiso in Gibson County, IN?

Gibson County is in Zone 7a with an average last frost of April 6. Plan your Shiso planting based on this frost date — see the calendar above for exact timing.

What planting zone is Gibson County, IN?

Gibson County, Indiana is in USDA Hardiness Zone 7a. The average last spring frost is April 6 and first fall frost is October 28.

🌱

Your Gibson County Garden Planner — Free

A 24-page printable planner built for Gibson 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 Gibson County, IN. 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.