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When to plant Shiso in Edwards County County,

Aim to plant Shiso in Edwards County County on or after April 16; the window stays open through May 7. Edwards County County's 202-day frost-free season gives you enough for a full main crop and a short fall succession.

When to Plant Shiso in Edwards County, IL

Edwards County, Illinois Zone 6b June

June to-do list for Edwards County, Illinois

Your Edwards County, Illinois garden is entering a new phase. Here's what's on the schedule for June and why each task matters now.

Avg. last frost April 9
Avg. first frost October 28
Soil temp (4") 74°F
Watering Low
Pest pressure High
Daylight 14.7 hrs
  1. Harvest shiso as they ripen

    Check every 1–2 days. Many of these get tough or go to seed if you wait too long.

To set up a strong July, finish these tasks
  • 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.

Edwards County, Illinois is in USDA Zone 6b. The average last spring frost is April 9 and the first fall frost is October 28, giving you a growing season of approximately 202 days.

At an elevation of 1,374 feet, Edwards County receives approximately 35.4 inches of rainfall annually with predominantly silt loam soil. Summer highs average 85°F, providing good warmth for Shiso during the growing season.

Edwards County, IL (Zone 6b) Long season
202 days
Last Spring Frost April 9
202 growing days
First Fall Frost October 28
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Edwards County Soil Profile

Soil Type

Silt Loam

Soil pH

6-7.2

Drainage

Well Drained

Shiso Planting Risk Windows

Early Start (70% safe) ✓ Fits season (76 days to spare)
Start indoors: Feb 12 Transplant: Apr 16 🍅 Harvest: Jun 11 – Aug 6
Recommended (50%) ✓ Fits season (76 days to spare)
Start indoors: Feb 19 Transplant: Apr 23 🍅 Harvest: Jun 18 – Aug 13
Safe Start (90%) ✓ Fits season (82 days to spare)
Start indoors: Mar 4 Transplant: May 6 🍅 Harvest: Jul 1 – Aug 26

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 Edwards County

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

Soil pH

Your soil pH (6.0–7.2) overlaps with Shiso's range (5.5–7.0), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is excellent (4.7%) — 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 202-day season

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

Shiso Water Budget

Plant needs
1.0″/week
Rainfall provides
0.7″/week
You supply
0.3″/week
Watering frequency Only during dry spells
Season total 475 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 1.6" 0" ❄️ Dormant
Feb 1.5" 0" ❄️ Dormant
Mar 2.5" 0" ❄️ Dormant
Apr 4.3" 3.2" 1.1" 💧 Light watering
May 4.3" 4" 0.3" 💧 Light watering
Jun 4.3" 5" 0" ✅ Rainfall sufficient
Jul 4.3" 3.9" 0.4" 💧 Light watering
Aug 4.3" 3.4" 0.9" 💧 Light watering
Sep 4.3" 3.1" 1.2" 💧 Light watering
Oct 4.3" 2.9" 1.4" 💧 Light watering
Nov 2.3" 0" ❄️ Dormant
Dec 2.1" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Edwards 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 ~825 GDD — county provides 2,777 GDD Excellent fit

Shiso Planting Timeline — Edwards County, IL

Shiso Planting Calendar

Activity When Date Range
Start Indoors February 19 Feb 19 – Mar 5
Transplant Outdoors April 23 Apr 23 – May 7
Direct Sow April 16 Apr 16 – May 7
Harvest June 18 Jun 18 – Aug 13

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: acceptable

🗺️ USDA Zone

Zone 6b

📆 Growing Season

202 days in Edwards County

Growing Tips for Shiso in Edwards County

Direct sow Shiso outdoors after April 09 in Edwards 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 Edwards County, IL?

Edwards County is in Zone 6b with an average last frost of April 9. Plan your Shiso planting based on this frost date — see the calendar above for exact timing.

What planting zone is Edwards County, IL?

Edwards County, Illinois is in USDA Hardiness Zone 6b. The average last spring frost is April 9 and first fall frost is October 28.

When should I plant Shiso in Edwards County, ?

In Edwards County, , plant Shiso after the last frost (around April 9) and before the first frost (around October 28). Best results when soil holds above 50°F.

What growing zone is Edwards County, for Shiso?

Edwards County sits in USDA Zone 6b. Shiso grows reliably in zones 3a through 11b, so it's a good fit here.

Can Shiso grow in Edwards County's climate?

Yes — Shiso grows well in Edwards County's temperate climate. Edwards County averages a 202-day frost-free season, with last frost around April 9 and first frost around October 28.

🌱

Your Edwards County Garden Planner — Free

A 22-page printable planner built for Edwards County (Zone 6b). 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 Edwards County, IL. 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.