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When to Plant Komatsuna in Mono County, CA

Mono County, California Zone 6b May

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

May rewards gardeners who work with the weather, not against it. Here's how to stay in step this month in Mono County, California.

Avg. last frost June 18
Avg. first frost August 20
Soil temp (4") 52°F
Watering Critical
Pest pressure Low
Daylight 14.1 hrs
June will be here before you know it — start on
  • Transplants going out: komatsuna
  • Direct-sowing: komatsuna
  • Fall sowing: komatsuna

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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.

Mono County, California is in USDA Zone 6b. The average last spring frost is June 18 and the first fall frost is August 20, giving you a growing season of approximately 63 days.

At an elevation of 2,381 feet, Mono County receives approximately 13.3 inches of rainfall annually with predominantly loam soil. Summer highs average 84°F, so choose short-season varieties of Komatsuna to ensure they mature before fall. With low rainfall, drip irrigation is essential for growing Komatsuna successfully. Mulch heavily to conserve soil moisture.

Mono County, CA (Zone 6b) Very short season
63 days
Last Spring Frost June 18
63 growing days
First Fall Frost August 20

Mono County Soil Profile

Soil Type

Loam

Soil pH

6-7.5

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (5 days to spare)
Start indoors: Apr 17 Transplant: May 22 🍅 Harvest: Jun 26 – Jul 31
Recommended (50%) ✗ May not fit
Start indoors: May 14 Transplant: Jun 18 🍅 Harvest: Jul 23 – Aug 27
Safe Start (90%) ✓ Fits season (56 days to spare)
Start indoors: May 26 Transplant: Jun 30 🍅 Harvest: Aug 4 – Sep 8

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 Mono County

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

Soil pH

Your soil pH (6.0–7.5) is within Komatsuna's preferred range (6.0–7.5).

Soil Texture

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

Organic Matter

Organic matter is moderate (2.5%). Annual compost additions will help Komatsuna.

How to Plant Komatsuna

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

Fall planting: Sow 10 weeks before your first frost date for a fall harvest.

Succession Planting Komatsuna

2
successive plantings in your 63-day season

Sow every 4 weeks. Last sowing by Jul 01 to harvest before frost.

For a dedicated fall crop, sow by Jun 11.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.9″/week
You supply
0.1″/week
Watering frequency Only during dry spells
Season total 76 gal / 100 sq ft
Drought risk

Water stress score is 10/10 — 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 2.7" 0" ❄️ Dormant
Feb 3.1" 0" ❄️ Dormant
Mar 1.9" 0" ❄️ Dormant
Apr 1" 0" ❄️ Dormant
May 0.3" 0" ❄️ Dormant
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 0.2" 0" ❄️ Dormant
Oct 0.6" 0" ❄️ Dormant
Nov 1.1" 0" ❄️ Dormant
Dec 2.4" 0" ❄️ Dormant

Water needs are for active growing months only (Jun–Aug in Mono 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 ~552 GDD — county provides 819 GDD Excellent fit

Komatsuna Planting Timeline — Mono County, CA

Komatsuna Planting Calendar

Activity When Date Range
Start Indoors May 14 May 14 – May 28
Transplant Outdoors June 18 Jun 18 – Jul 2
Direct Sow June 4 Jun 4 – Jun 25
Harvest July 23 Jul 23 – Aug 27
Fall Sowing June 11 Jun 11 – Jun 25

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Partial Shade (3-6 hours)

💧 Water

1"/week · Only during dry spells

📅 Days to Maturity

35–50 days

🧪 Soil pH

Needs 6–7.5 · Your soil: ideal

🗺️ USDA Zone

Zone 6b

📆 Growing Season

63 days in Mono County

Growing Tips for Komatsuna in Mono County

Direct sow Komatsuna outdoors after June 18 in Mono County when soil has warmed and frost danger has passed.

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

Mono County receives only 13" 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 Mono County, CA?

Mono County is in Zone 6b with an average last frost of June 18. Plan your Komatsuna planting based on this frost date — see the calendar above for exact timing.

What planting zone is Mono County, CA?

Mono County, California is in USDA Hardiness Zone 6b. The average last spring frost is June 18 and first fall frost is August 20.

🌱

Your Mono County Garden Planner — Free

A 24-page printable planner built for Mono County (Zone 6b). 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 Mono 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.