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When to Plant Shiso in Jackson County, OH

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.

Jackson County, Ohio is in USDA Zone 6a. The average last spring frost is April 21 and the first fall frost is October 22, giving you a growing season of approximately 184 days.

At an elevation of 831 feet, Jackson County receives approximately 31.1 inches of rainfall annually with predominantly silt loam soil. Summer highs average 90ยฐF, providing good warmth for Shiso during the growing season.

Jackson County, OH (Zone 6a) Moderate season
184 days
Last Spring Frost April 21
184 growing days
First Fall Frost October 22

Jackson County Soil Profile

Soil Type

Silt Loam

Soil pH

6.2-6.8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (61 days to spare)
Start indoors: Feb 23 Transplant: Apr 27 🍅 Harvest: Jun 22 – Aug 17
Recommended (50%) ✓ Fits season (58 days to spare)
Start indoors: Mar 3 Transplant: May 5 🍅 Harvest: Jun 30 – Aug 25
Safe Start (90%) ✓ Fits season (54 days to spare)
Start indoors: Mar 18 Transplant: May 20 🍅 Harvest: Jul 15 – Sep 9

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 Jackson County

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

Soil pH

Your soil pH (6.2โ€“6.8) is within Shiso's preferred range (5.5โ€“7.0).

Soil Texture

The silt loam soil in Jackson County is excellent for Shiso โ€” good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is excellent (4.1%) โ€” 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 184-day season

Sow every 5.7 weeks. Last sowing by Aug 13 to harvest before frost.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.7″/week
You supply
0.4″/week
Watering frequency 1-2 times/week
Season total 570 gal / 100 sq ft
Drought risk

Water stress score is 6/10 โ€” 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 โ€” 1.4" 0" โ„๏ธ Dormant
Feb โ€” 1.5" 0" โ„๏ธ Dormant
Mar โ€” 2.2" 0" โ„๏ธ Dormant
Apr 4.3" 3" 1.3" ๐Ÿ’ง Light watering
May 4.3" 3.7" 0.6" ๐Ÿ’ง Light watering
Jun 4.3" 4.2" 0.1" ๐Ÿ’ง Light watering
Jul 4.3" 3.3" 1" ๐Ÿ’ง Light watering
Aug 4.3" 3.4" 0.9" ๐Ÿ’ง Light watering
Sep 4.3" 2.7" 1.6" ๐Ÿ’ง Light watering
Oct 4.3" 2.3" 2" ๐Ÿ’ง Light watering
Nov โ€” 1.9" 0" โ„๏ธ Dormant
Dec โ€” 1.5" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Aprโ€“Oct in Jackson County). Supplement amounts are based on average rainfall โ€” 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" โ€” every day above 50ยฐF 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 ~1,050 GDD — county provides 3,220 GDD Excellent fit

Shiso Planting Timeline โ€” Jackson County, OH

Shiso Planting Calendar

Activity When Date Range
Start Indoors March 3 Mar 3 โ€“ Mar 17
Transplant Outdoors May 5 May 5 โ€“ May 19
Direct Sow April 28 Apr 28 โ€“ May 19
Harvest June 30 Jun 30 โ€“ Aug 25

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

Month-by-Month Timeline

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

Growing Conditions

โ˜€๏ธ Sun

Partial Shade (3-6 hours)

๐Ÿ’ง Water

1"/week ยท 1-2 times/week

๐Ÿ“… Days to Maturity

50โ€“70 days

๐Ÿงช Soil pH

Needs 5.5โ€“7 ยท Your soil: ideal

๐Ÿ—บ๏ธ USDA Zone

Zone 6a

๐Ÿ“† Growing Season

184 days in Jackson County

Growing Tips for Shiso in Jackson County

Direct sow Shiso outdoors after April 21 in Jackson 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 Jackson County, OH?

Jackson County is in Zone 6a with an average last frost of April 21. Plan your Shiso planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Jackson County, OH?

Jackson County, Ohio is in USDA Hardiness Zone 6a. The average last spring frost is April 21 and first fall frost is October 22.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Jackson County gardeners in Zone 6a organize planting dates, track what's growing, and never miss a planting window.

Get Your Free Garden Planner →

Free download. Plan your entire garden season in minutes.

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Jackson County, OH. Local conditions may vary. Last updated: April 2026.