Blog

When to Plant Shiso in Sutter County, CA

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.

Sutter County, California is in USDA Zone 9a. The average last spring frost is March 4 and the first fall frost is November 26, giving you a growing season of approximately 267 days.

At an elevation of 484 feet, Sutter County receives approximately 21.4 inches of rainfall annually with predominantly loam soil. Summer highs average 88ยฐF, providing good warmth for Shiso during the growing season.

Sutter County, CA (Zone 9a) Long season
267 days
Last Spring Frost March 4
267 growing days
First Fall Frost November 26

Sutter County Soil Profile

Soil Type

Loam

Soil pH

6.8-7.7

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (160 days to spare)
Start indoors: Dec 27 Transplant: Feb 14 🍅 Harvest: Apr 11 – Jun 6
Recommended (50%) ✓ Fits season (148 days to spare)
Start indoors: Jan 21 Transplant: Mar 11 🍅 Harvest: May 6 – Jul 1
Safe Start (90%) ✓ Fits season (115 days to spare)
Start indoors: Mar 16 Transplant: May 4 🍅 Harvest: Jun 29 – Aug 24

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 Sutter County

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

Soil pH

Your soil pH (6.8โ€“7.7) is more alkaline than Shiso prefers (5.5โ€“7.0). Add sulfur or peat moss to lower pH.

Soil Texture

The loam soil in Sutter County is excellent for Shiso โ€” good drainage, moisture retention, and nutrient holding capacity.

Drainage

Drainage is adequate for Shiso.

Organic Matter

Organic matter is moderate (2.4%). Annual compost additions will help Shiso.

How to Plant Shiso

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

Succession Planting Shiso

6
successive plantings in your 267-day season

Sow every 5.7 weeks. Last sowing by Sep 17 to harvest before frost.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.3″/week
You supply
1.2″/week
Watering frequency 2-3 times/week
Season total 2,747 gal / 100 sq ft
Drought risk

Water stress score is 8/10 โ€” 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 โ€” 4.6" 0" โ„๏ธ Dormant
Feb โ€” 4.2" 0" โ„๏ธ Dormant
Mar 4.3" 3.7" 0.6" ๐Ÿ’ง Light watering
Apr 4.3" 1.4" 2.9" ๐Ÿšฟ Regular watering
May 4.3" 0.6" 3.7" ๐Ÿšฟ Regular watering
Jun 4.3" 0.1" 4.2" ๐Ÿšฟ Regular watering
Jul 4.3" 0" 4.3" ๐Ÿšฟ Regular watering
Aug 4.3" 0" 4.3" ๐Ÿšฟ Regular watering
Sep 4.3" 0.2" 4.1" ๐Ÿšฟ Regular watering
Oct 4.3" 0.9" 3.4" ๐Ÿšฟ Regular watering
Nov 4.3" 1.8" 2.5" ๐Ÿšฟ Regular watering
Dec โ€” 3.8" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Marโ€“Nov in Sutter County). Supplement amounts are based on average rainfall โ€” 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" โ€” every day above 50ยฐF 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 4,272 GDD Excellent fit

Shiso Planting Timeline โ€” Sutter County, CA

Shiso Planting Calendar

Activity When Date Range
Start Indoors January 21 Jan 21 โ€“ Feb 4
Transplant Outdoors March 11 Mar 11 โ€“ Mar 25
Direct Sow March 11 Mar 11 โ€“ Apr 1
Harvest May 6 May 6 โ€“ Jul 1

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

Month-by-Month Timeline

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

Growing Conditions

โ˜€๏ธ Sun

Partial Shade (3-6 hours)

๐Ÿ’ง Water

1"/week ยท 2-3 times/week

๐Ÿ“… Days to Maturity

50โ€“70 days

๐Ÿงช Soil pH

Needs 5.5โ€“7 ยท Your soil: too_alkaline

๐Ÿ—บ๏ธ USDA Zone

Zone 9a

๐Ÿ“† Growing Season

267 days in Sutter County

Growing Tips for Shiso in Sutter County

Direct sow Shiso outdoors after March 04 in Sutter County when soil has warmed and frost danger has passed.

Sutter County receives only 21" of rain annually. Shiso needs consistent moisture โ€” 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 Sutter County, CA?

Sutter County is in Zone 9a with an average last frost of March 4. Plan your Shiso planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Sutter County, CA?

Sutter County, California is in USDA Hardiness Zone 9a. The average last spring frost is March 4 and first fall frost is November 26.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Sutter County gardeners in Zone 9a organize planting dates, track what's growing, and never miss a planting window.

Get Your Free Garden Planner →

Free download. Plan your entire garden season in minutes.

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Sutter County, CA. Local conditions may vary. Last updated: April 2026.