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When to plant Shiso in Hancock County, IL

Aim to plant Shiso in Hancock County on or after April 21; the window stays open through May 12. Hancock County's 187-day frost-free season gives you enough for a full main crop and a short fall succession.

When to Plant Shiso in Hancock County, IL

Hancock County, Illinois Zone 6a June

June to-do list for Hancock County, Illinois

Welcome to June in Zone 6a. These are the moves that will have the biggest impact on your growing season.

Avg. last frost April 14
Avg. first frost October 18
Soil temp (4") 69°F
Watering Low
Pest pressure High
Daylight 14.9 hrs
  1. Get shiso seeds going inside

    These need a head start before your last frost (April 14). Sow into cells now so you're ready to transplant in a few weeks.

  2. Pick shiso

    Don't tug. Use scissors or pruners for clean cuts — torn stems invite disease.

Looking ahead to July
  • 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.

Hancock County, Illinois is in USDA Zone 6a. The average last spring frost is April 14 and the first fall frost is October 18, giving you a growing season of approximately 187 days.

At an elevation of 758 feet, Hancock County receives approximately 37.1 inches of rainfall annually with predominantly silt loam soil. Summer highs average 87°F, providing good warmth for Shiso during the growing season.

Hancock County, IL (Zone 6a) Moderate season
187 days
Last Spring Frost April 14
187 growing days
First Fall Frost October 18

Hancock County Soil Profile

Soil Type

Silt Loam

Soil pH

5.9-6.8

Drainage

Well Drained

Shiso Planting Risk Windows

Early Start (70% safe) ✓ Fits season (60 days to spare)
Start indoors: Feb 19 Transplant: Apr 23 🍅 Harvest: Jun 18 – Aug 13
Recommended (50%) ✓ Fits season (61 days to spare)
Start indoors: Feb 24 Transplant: Apr 28 🍅 Harvest: Jun 23 – Aug 18
Safe Start (90%) ✓ Fits season (59 days to spare)
Start indoors: Mar 11 Transplant: May 13 🍅 Harvest: Jul 8 – Sep 2

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 Hancock County

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

Soil pH

Your soil pH (5.9–6.8) is within Shiso's preferred range (5.5–7.0).

Soil Texture

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

Drainage

Drainage is adequate for Shiso.

Organic Matter

Organic matter is excellent (4.9%) — 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 187-day season

Sow every 5.7 weeks. Last sowing by Aug 09 to harvest before frost.

Shiso Water Budget

Plant needs
1.0″/week
Rainfall provides
0.8″/week
You supply
0.5″/week
Watering frequency 1-2 times/week
Season total 777 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 1.5" 0" ❄️ Dormant
Feb 1.5" 0" ❄️ Dormant
Mar 2.7" 0" ❄️ Dormant
Apr 4.3" 3.1" 1.2" 💧 Light watering
May 4.3" 4.2" 0.1" 💧 Light watering
Jun 4.3" 4.4" 0" ✅ Rainfall sufficient
Jul 4.3" 4.6" 0" ✅ Rainfall sufficient
Aug 4.3" 4.2" 0.1" 💧 Light watering
Sep 4.3" 3.3" 1" 💧 Light watering
Oct 4.3" 3.1" 1.2" 💧 Light watering
Nov 2.7" 0" ❄️ Dormant
Dec 1.8" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Hancock 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 ~915 GDD — county provides 2,851 GDD Excellent fit

Shiso Planting Timeline — Hancock County, IL

Shiso Planting Calendar

Activity When Date Range
Start Indoors February 24 Feb 24 – Mar 10
Transplant Outdoors April 28 Apr 28 – May 12
Direct Sow April 21 Apr 21 – May 12
Harvest June 23 Jun 23 – Aug 18

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

Partial Shade (3-6 hours)

💧 Water

1"/week · 1-2 times/week

📅 Days to Maturity

50–70 days

🧪 Soil pH

Needs 5.5–7 · Your soil: ideal

🗺️ USDA Zone

Zone 6a

📆 Growing Season

187 days in Hancock County

Growing Tips for Shiso in Hancock County

Direct sow Shiso outdoors after April 14 in Hancock 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 Hancock County, IL?

Hancock County is in Zone 6a with an average last frost of April 14. Plan your Shiso planting based on this frost date — see the calendar above for exact timing.

What planting zone is Hancock County, IL?

Hancock County, Illinois is in USDA Hardiness Zone 6a. The average last spring frost is April 14 and first fall frost is October 18.

When should I plant Shiso in Hancock County, IL?

In Hancock County, IL, plant Shiso after the last frost (around April 14) and before the first frost (around October 18). Best results when soil holds above 50°F.

What growing zone is Hancock County, IL for Shiso?

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

Can Shiso grow in Hancock County's climate?

Yes — Shiso grows well in Hancock County's temperate climate. Hancock County averages a 187-day frost-free season, with last frost around April 14 and first frost around October 18.

🌱

Your Hancock County Garden Planner — Free

A 22-page printable planner built for Hancock County (Zone 6a). 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 Hancock 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.