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When to Plant Shiso in Caddo County, OK

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.

Caddo County, Oklahoma is in USDA Zone 7b. The average last spring frost is April 4 and the first fall frost is November 4, giving you a growing season of approximately 214 days.

At an elevation of 762 feet, Caddo County receives approximately 32.1 inches of rainfall annually with predominantly loam soil. Summer highs average 89°F, providing good warmth for Shiso during the growing season.

Caddo County, OK (Zone 7b) Long season
214 days
Last Spring Frost April 4
214 growing days
First Fall Frost November 4

Caddo County Soil Profile

Soil Type

Loam

Soil pH

6.3-7.4

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 0.7" 0" ❄️ Dormant
Feb 1.2" 0" ❄️ Dormant
Mar 2.1" 0" ❄️ Dormant
Apr 4.3" 3.5" 0.8" 💧 Light watering
May 4.3" 4.8" 0" ✅ Rainfall sufficient
Jun 4.3" 5.1" 0" ✅ Rainfall sufficient
Jul 4.3" 4.2" 0.1" 💧 Light watering
Aug 4.3" 4" 0.3" 💧 Light watering
Sep 4.3" 3.1" 1.2" 💧 Light watering
Oct 4.3" 1.7" 2.6" 🚿 Regular watering
Nov 4.3" 1" 3.3" 🚿 Regular watering
Dec 0.7" 0" ❄️ Dormant

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

Shiso Planting Timeline — Caddo County, OK

Shiso Planting Calendar

Activity When Date Range
Start Indoors February 14 Feb 14 – Feb 28
Transplant Outdoors April 18 Apr 18 – May 2
Direct Sow April 11 Apr 11 – May 2
Harvest June 13 Jun 13 – Aug 8

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

Month-by-Month Timeline

MonthActivities
January
February Start Indoors
March
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 7b

📆 Growing Season

214 days in Caddo County

Growing Tips for Caddo 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 Caddo County, OK?

Caddo County is in Zone 7b with an average last frost of April 4. Plan your Shiso planting based on this frost date — see the calendar above for exact timing.

What planting zone is Caddo County, OK?

Caddo County, Oklahoma is in USDA Hardiness Zone 7b. The average last spring frost is April 4 and first fall frost is November 4.

🌱

Your Caddo County Garden Planner — Free

A 22-page printable planner built for Caddo County (Zone 7b). 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 Caddo County, OK. 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.