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When to Plant Shiso in Grant County, WI

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.

Grant County, Wisconsin is in USDA Zone 5a. The average last spring frost is April 28 and the first fall frost is October 8, giving you a growing season of approximately 163 days.

At an elevation of 884 feet, Grant County receives approximately 37.9 inches of rainfall annually with predominantly silt loam soil. Summer highs average 81°F, so choose short-season varieties of Shiso to ensure they mature before fall.

Grant County, WI (Zone 5a) Moderate season
163 days
Last Spring Frost April 28
163 growing days
First Fall Frost October 8

Grant County Soil Profile

Soil Type

Silt Loam

Soil pH

6.0-7.0

Drainage

Well Drained

Shiso Planting Timeline — Grant County, WI

Shiso Planting Calendar

Activity When Date Range
Start Indoors March 10 Mar 10 – Mar 24
Transplant Outdoors May 12 May 12 – May 26
Direct Sow May 5 May 5 – May 26
Harvest July 7 Jul 7 – Sep 1

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

Month-by-Month Timeline

MonthActivities
January
February
March Start Indoors
April
May Transplant Outdoors Direct Sow
June
July Harvest
August Harvest
September Harvest
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 5a

📆 Growing Season

163 days in Grant County

Growing Tips for Grant 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 Grant County, WI?

Grant County is in Zone 5a with an average last frost of April 28. Plan your Shiso planting based on this frost date — see the calendar above for exact timing.

What planting zone is Grant County, WI?

Grant County, Wisconsin is in USDA Hardiness Zone 5a. The average last spring frost is April 28 and first fall frost is October 8.

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Your Grant County Garden Planner — Free

A 22-page printable planner built for Grant County (Zone 5a). 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 Grant County, WI. 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.