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When to Plant Shiso in Henderson County, KY

Henderson County, Kentucky Zone 7a May

May in the garden — Henderson County, Kentucky

Your garden in Henderson County, Kentucky is working on a schedule, even when you're not. Here's where you should be this May.

Avg. last frost April 5
Avg. first frost October 31
Soil temp (4") 55°F
Watering Low
Pest pressure Low
Daylight 14 hrs
  1. Indoor seed-starting week for shiso

    These need a head start before your last frost (April 5). Sow into cells now so you're ready to transplant in a few weeks.

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

Henderson County, Kentucky is in USDA Zone 7a. The average last spring frost is April 5 and the first fall frost is October 31, giving you a growing season of approximately 209 days.

At an elevation of 3,992 feet, Henderson County receives approximately 47.6 inches of rainfall annually with predominantly silt loam soil. Summer highs average 89°F, providing good warmth for Shiso during the growing season.

Henderson County, KY (Zone 7a) Long season
209 days
Last Spring Frost April 5
209 growing days
First Fall Frost October 31
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Henderson County Soil Profile

Soil Type

Silt Loam

Soil pH

5.3-7.1

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (83 days to spare)
Start indoors: Feb 8 Transplant: Apr 12 🍅 Harvest: Jun 7 – Aug 2
Recommended (50%) ✓ Fits season (83 days to spare)
Start indoors: Feb 15 Transplant: Apr 19 🍅 Harvest: Jun 14 – Aug 9
Safe Start (90%) ✓ Fits season (91 days to spare)
Start indoors: Feb 28 Transplant: May 2 🍅 Harvest: Jun 27 – Aug 22

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 Henderson County

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

Soil pH

Your soil pH (5.3–7.1) overlaps with Shiso's range (5.5–7.0), though not a perfect match.

Soil Texture

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

Drainage

Drainage is adequate for Shiso.

Organic Matter

Organic matter is moderate (2.6%). Annual compost additions will help Shiso.

How to Plant Shiso

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

Succession Planting Shiso

4
successive plantings in your 209-day season

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

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
1.0″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft
Drought risk

Water stress score is 6/10 — consider drought-tolerant varieties and mulching

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 3.6" 0" ❄️ Dormant
Feb 3.3" 0" ❄️ Dormant
Mar 4.9" 0" ❄️ Dormant
Apr 4.3" 4" 0.3" 💧 Light watering
May 4.3" 4.2" 0.1" 💧 Light watering
Jun 4.3" 4.5" 0" ✅ Rainfall sufficient
Jul 4.3" 4.5" 0" ✅ Rainfall sufficient
Aug 4.3" 4.9" 0" ✅ Rainfall sufficient
Sep 4.3" 3.3" 1" 💧 Light watering
Oct 4.3" 2.8" 1.5" 💧 Light watering
Nov 3.5" 0" ❄️ Dormant
Dec 3.9" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Henderson 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 ~1,005 GDD — county provides 3,500 GDD Excellent fit

Shiso Planting Timeline — Henderson County, KY

Shiso Planting Calendar

Activity When Date Range
Start Indoors February 15 Feb 15 – Mar 1
Transplant Outdoors April 19 Apr 19 – May 3
Direct Sow April 12 Apr 12 – May 3
Harvest June 14 Jun 14 – Aug 9

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 · Natural rainfall sufficient

📅 Days to Maturity

50–70 days

🧪 Soil pH

Needs 5.5–7 · Your soil: acceptable

🗺️ USDA Zone

Zone 7a

📆 Growing Season

209 days in Henderson County

Growing Tips for Shiso in Henderson County

Direct sow Shiso outdoors after April 05 in Henderson 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 Henderson County, KY?

Henderson County is in Zone 7a with an average last frost of April 5. Plan your Shiso planting based on this frost date — see the calendar above for exact timing.

What planting zone is Henderson County, KY?

Henderson County, Kentucky is in USDA Hardiness Zone 7a. The average last spring frost is April 5 and first fall frost is October 31.

🌱

Your Henderson County Garden Planner — Free

A 24-page printable planner built for Henderson 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 Henderson County, KY. 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.