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When to Plant Shiso in Inyo County, CA

Inyo County, California Zone 8b May

Your May gardening checklist

Welcome to May in Zone 8b. These are the moves that will have the biggest impact on your growing season.

Avg. last frost January 15
Avg. first frost December 10
Soil temp (4") 57°F
Watering Critical
Pest pressure Moderate
Daylight 13.9 hrs
  1. Pick shiso

    Check every 1–2 days. Many of these get tough or go to seed if you wait too long.

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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.

Inyo County, California is in USDA Zone 8b. The average last spring frost is January 15 and the first fall frost is December 10, giving you a growing season of approximately 329 days.

At an elevation of 4,562 feet, Inyo County receives approximately 16.4 inches of rainfall annually with predominantly loam soil. Summer highs average 88°F, providing good warmth for Shiso during the growing season. With low rainfall, drip irrigation is essential for growing Shiso successfully. Mulch heavily to conserve soil moisture.

Inyo County, CA (Zone 8b) Year-round
329 days
Last Spring Frost January 15
329 growing days
First Fall Frost December 10

Inyo County Soil Profile

Soil Type

Loam

Soil pH

6-7.8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (206 days to spare)
Start indoors: Nov 19 Transplant: Jan 21 🍅 Harvest: Mar 18 – May 13
Recommended (50%) ✓ Fits season (203 days to spare)
Start indoors: Nov 27 Transplant: Jan 29 🍅 Harvest: Mar 26 – May 21
Safe Start (90%) ✓ Fits season (189 days to spare)
Start indoors: Dec 22 Transplant: Feb 23 🍅 Harvest: Apr 20 – Jun 15

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 Inyo County

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

Soil pH

Your soil pH (6.0–7.8) overlaps with Shiso's range (5.5–7.0), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is moderate (2.2%). Annual compost additions will help Shiso.

How to Plant Shiso

0.5"
Planting Depth
8"
Between Plants
12"
Between Rows

Succession Planting Shiso

7
successive plantings in your 329-day season

Sow every 5.7 weeks. Last sowing by Oct 01 to harvest before frost.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.2″/week
You supply
1.0″/week
Watering frequency 2-3 times/week
Season total 2,789 gal / 100 sq ft
Drought risk

Water stress score is 10/10 — consider drought-tolerant varieties and mulching

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 4.3" 3.3" 1" 💧 Light watering
Feb 4.3" 3.4" 0.9" 💧 Light watering
Mar 4.3" 2.5" 1.8" 💧 Light watering
Apr 4.3" 1.3" 3" 🚿 Regular watering
May 4.3" 0.5" 3.8" 🚿 Regular watering
Jun 4.3" 0.1" 4.2" 🚿 Regular watering
Jul 4.3" 0" 4.3" 🚿 Regular watering
Aug 4.3" 0" 4.3" 🚿 Regular watering
Sep 4.3" 0.2" 4.1" 🚿 Regular watering
Oct 4.3" 0.6" 3.7" 🚿 Regular watering
Nov 4.3" 1.7" 2.6" 🚿 Regular watering
Dec 4.3" 2.8" 1.5" 💧 Light watering

Water needs are for active growing months only (Jan–Dec in Inyo 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 ~960 GDD — county provides 5,280 GDD Excellent fit

Shiso Planting Timeline — Inyo County, CA

Shiso Planting Calendar

Activity When Date Range
Start Indoors November 27 Nov 27 – Dec 11
Transplant Outdoors January 29 Jan 29 – Feb 12
Direct Sow January 22 Jan 22 – Feb 12
Harvest March 26 Mar 26 – May 21

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

Month-by-Month Timeline

MonthActivities
January Transplant Outdoors Direct Sow
February Transplant Outdoors Direct Sow
March Harvest
April Harvest
May Harvest
June
July
August
September
October
November Start Indoors
December Start Indoors

Growing Conditions

☀️ Sun

Partial Shade (3-6 hours)

💧 Water

1"/week · 2-3 times/week

📅 Days to Maturity

50–70 days

🧪 Soil pH

Needs 5.5–7 · Your soil: acceptable

🗺️ USDA Zone

Zone 8b

📆 Growing Season

329 days in Inyo County

Growing Tips for Shiso in Inyo County

Direct sow Shiso outdoors after January 15 in Inyo County when soil has warmed and frost danger has passed.

Inyo County receives only 16" of rain annually. Shiso needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.

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 Inyo County, CA?

Inyo County is in Zone 8b with an average last frost of January 15. Plan your Shiso planting based on this frost date — see the calendar above for exact timing.

What planting zone is Inyo County, CA?

Inyo County, California is in USDA Hardiness Zone 8b. The average last spring frost is January 15 and first fall frost is December 10.

🌱

Your Inyo County Garden Planner — Free

A 24-page printable planner built for Inyo County (Zone 8b). 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 Inyo County, CA. Local conditions may vary. Last updated: May 2026.

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.