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When to plant Shiso in Calhoun County, IL

Calhoun County's spring Shiso window runs April 20 through May 11. time plantings around the expected last-frost window for best survival.

When to Plant Shiso in Calhoun County, IL

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.

Calhoun County, Illinois is in USDA Zone 6b. The average last spring frost is April 13 and the first fall frost is October 21, giving you a growing season of approximately 191 days.

At an elevation of 731 feet, Calhoun County receives approximately 32.2 inches of rainfall annually with predominantly silt loam soil. Summer highs average 86°F, providing good warmth for Shiso during the growing season.

Calhoun County, IL (Zone 6b) Moderate season
191 days
Last Spring Frost April 13
191 growing days
First Fall Frost October 21

Calhoun County Soil Profile

Soil Type

Silt Loam

Soil pH

6-7.3

Drainage

Well Drained

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 1.3" 0" ❄️ Dormant
Feb 1.4" 0" ❄️ Dormant
Mar 2" 0" ❄️ Dormant
Apr 4.3" 3" 1.3" 💧 Light watering
May 4.3" 3.8" 0.5" 💧 Light watering
Jun 4.3" 4.6" 0" ✅ Rainfall sufficient
Jul 4.3" 3.7" 0.6" 💧 Light watering
Aug 4.3" 3" 1.3" 💧 Light watering
Sep 4.3" 3.3" 1" 💧 Light watering
Oct 4.3" 2.2" 2.1" 💧 Light watering
Nov 2.4" 0" ❄️ Dormant
Dec 1.6" 0" ❄️ Dormant

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

Shiso Planting Timeline — Calhoun County, IL

Shiso Planting Calendar

Activity When Date Range
Start Indoors February 23 Feb 23 – Mar 9
Transplant Outdoors April 27 Apr 27 – May 11
Direct Sow April 20 Apr 20 – May 11
Harvest June 22 Jun 22 – Aug 17

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

Moderate — regular watering

📅 Days to Maturity

50–70 days

🧪 Soil pH

Needs 5.5–7 · Your soil: N/A

🗺️ USDA Zone

Zone 6b

📆 Growing Season

191 days in Calhoun County

Growing Tips for Calhoun County

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 Calhoun County, IL?

Calhoun County is in Zone 6b with an average last frost of April 13. Plan your Shiso planting based on this frost date — see the calendar above for exact timing.

What planting zone is Calhoun County, IL?

Calhoun County, Illinois is in USDA Hardiness Zone 6b. The average last spring frost is April 13 and first fall frost is October 21.

When should I plant Shiso in Calhoun County, IL?

In Calhoun County, IL, plant Shiso after the last frost (around April 13) and before the first frost (around October 21). Best results when soil holds above 50°F.

What growing zone is Calhoun County, IL for Shiso?

Calhoun 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 Calhoun County's climate?

Yes — Shiso grows well in Calhoun County's temperate climate. Calhoun County averages a 191-day frost-free season, with last frost around April 13 and first frost around October 21.

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Your Calhoun County Garden Planner — Free

A 22-page printable planner built for Calhoun 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 Calhoun County, IL. Local conditions may vary. Last updated: July 2026.

Sources & credits

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