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When to Plant Komatsuna in Sutter County, CA

Sutter County, California Zone 9b May

Sutter County, California gardeners: here's your May plan

Your Sutter County, California garden is entering a new phase. Here's what's on the schedule for May and why each task matters now.

Avg. last frost March 4
Avg. first frost November 26
Soil temp (4") 76°F
Watering Critical
Pest pressure High
Daylight 14.1 hrs
  1. Harvest komatsuna as they ripen

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

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Komatsuna (Japanese mustard spinach) is a versatile Asian green with glossy, dark leaves and a mild, sweet flavor. It is extremely cold-hardy and heat-tolerant.

Sutter County, California is in USDA Zone 9b. 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 88°F, providing good warmth for Komatsuna during the growing season.

Sutter County, CA (Zone 9b) 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 (209 days to spare)
Start indoors: Jan 10 Transplant: Feb 7 🍅 Harvest: Mar 14 – Apr 18
Recommended (50%) ✓ Fits season (197 days to spare)
Start indoors: Feb 4 Transplant: Mar 4 🍅 Harvest: Apr 8 – May 13
Safe Start (90%) ✓ Fits season (164 days to spare)
Start indoors: Mar 30 Transplant: Apr 27 🍅 Harvest: Jun 1 – Jul 6

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 Komatsuna's growing requirements.

Soil pH

Your soil pH (6.8–7.7) overlaps with Komatsuna's range (6.0–7.5), though not a perfect match.

Soil Texture

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

Drainage

Drainage is adequate for Komatsuna.

Organic Matter

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

How to Plant Komatsuna

0.5"
Planting Depth
6"
Between Plants
12"
Between Rows

Fall planting: Sow 8 weeks before your first frost date for a fall harvest.

Succession Planting Komatsuna

9
successive plantings in your 267-day season

Sow every 4 weeks. Last sowing by Oct 07 to harvest before frost.

For a dedicated fall crop, sow by Oct 01.

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 — consider drought-tolerant varieties and mulching

Monthly Watering Guide for Komatsuna

Komatsuna needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.

Month Komatsuna Needs Rainfall You Supplement Action
Jan 4.6" 0" ❄️ Dormant
Feb 4.2" 0" ❄️ Dormant
Mar 4.3" 3.7" 0.6" 💧 Light watering
Apr 4.3" 1.4" 2.9" 🚿 Regular watering
May 4.3" 0.6" 3.7" 🚿 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" 0.9" 3.4" 🚿 Regular watering
Nov 4.3" 1.8" 2.5" 🚿 Regular watering
Dec 3.8" 0" ❄️ Dormant

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

Komatsuna 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.

Komatsuna needs ~680 GDD — county provides 4,272 GDD Excellent fit

Komatsuna Planting Timeline — Sutter County, CA

Komatsuna Planting Calendar

Activity When Date Range
Start Indoors February 4 Feb 4 – Feb 18
Transplant Outdoors March 4 Mar 4 – Mar 18
Direct Sow February 11 Feb 11 – Mar 4
Harvest April 8 Apr 8 – May 13
Fall Sowing October 1 Oct 1 – Oct 15

Plant 0.5" deep · 6" apart · Rows 12" apart

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Partial Shade (3-6 hours)

💧 Water

1"/week · 2-3 times/week

📅 Days to Maturity

35–50 days

🧪 Soil pH

Needs 6–7.5 · Your soil: acceptable

🗺️ USDA Zone

Zone 9b

📆 Growing Season

267 days in Sutter County

Growing Tips for Komatsuna in Sutter County

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

Your generous 267.0-day season in Sutter County allows multiple plantings of Komatsuna. Sow every 17.0 days for continuous harvest.

Common pests for Komatsuna in this region include cabbage worm and flea beetles. Use row covers early in the season and inspect plants weekly.

Sutter County receives only 21" of rain annually. Komatsuna needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.

General growing tips

Direct sow in spring or fall. One of the most forgiving Asian greens for all seasons. Harvest outer leaves or cut whole plants. Excellent for stir-fries, soups, or salads.

Companion Planting

Good Companions

Avoid Planting Near

  • Strawberries

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Komatsuna in Sutter County, CA?

Sutter County is in Zone 9b with an average last frost of March 4. Plan your Komatsuna planting based on this frost date — see the calendar above for exact timing.

What planting zone is Sutter County, CA?

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

🌱

Your Sutter County Garden Planner — Free

A 24-page printable planner built for Sutter County (Zone 9b). 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 Sutter 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.