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When to plant Shiso in Adams County, IL

Adams County's spring Shiso window runs April 21 through May 12. time plantings around the expected last-frost window for best survival.

When to Plant Shiso in Adams 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.

Adams County, Illinois is in USDA Zone 6a. The average last spring frost is April 14 and the first fall frost is October 20, giving you a growing season of approximately 189 days.

At an elevation of 1,390 feet, Adams County receives approximately 33.1 inches of rainfall annually with predominantly silt loam soil. Summer highs average 85°F, providing good warmth for Shiso during the growing season.

Adams County, IL (Zone 6a) Moderate season
189 days
Last Spring Frost April 14
189 growing days
First Fall Frost October 20

Adams County Soil Profile

Soil Type

Silt Loam

Soil pH

6.2-7.3

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 1.5" 0" ❄️ Dormant
Feb 1.3" 0" ❄️ Dormant
Mar 2.1" 0" ❄️ Dormant
Apr 4.3" 3" 1.3" 💧 Light watering
May 4.3" 4" 0.3" 💧 Light watering
Jun 4.3" 4.5" 0" ✅ Rainfall sufficient
Jul 4.3" 3.7" 0.6" 💧 Light watering
Aug 4.3" 3.5" 0.8" 💧 Light watering
Sep 4.3" 3.1" 1.2" 💧 Light watering
Oct 4.3" 2.5" 1.8" 💧 Light watering
Nov 2.3" 0" ❄️ Dormant
Dec 1.6" 0" ❄️ Dormant

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

Shiso Planting Timeline — Adams 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

Moderate — regular watering

📅 Days to Maturity

50–70 days

🧪 Soil pH

Needs 5.5–7 · Your soil: N/A

🗺️ USDA Zone

Zone 6a

📆 Growing Season

189 days in Adams County

Growing Tips for Adams 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 Adams County, IL?

Adams 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 Adams County, IL?

Adams County, Illinois is in USDA Hardiness Zone 6a. The average last spring frost is April 14 and first fall frost is October 20.

When should I plant Shiso in Adams County, IL?

In Adams County, IL, plant Shiso after the last frost (around April 14) and before the first frost (around October 20). Best results when soil holds above 50°F.

What growing zone is Adams County, IL for Shiso?

Adams 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 Adams County's climate?

Yes — Shiso grows well in Adams County's temperate climate. Adams County averages a 189-day frost-free season, with last frost around April 14 and first frost around October 20.

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Your Adams County Garden Planner — Free

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

Sources & credits

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