When to Plant Komatsuna in Los Angeles County, CA
Los Angeles County, California gardeners: here's your May plan
Your Los Angeles County, California garden is entering a new phase. Here's what's on the schedule for May and why each task matters now.
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Fire up the seed-starting tray: komatsuna
Label every cell. You will absolutely forget which is which otherwise.
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Start harvesting komatsuna
The more you pick, the more the plant produces. Letting fruit overripen tells the plant it's time to stop.
June prep starts now
- First harvests: komatsuna
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.
Los Angeles County, California is in USDA Zone 10b. The average last spring frost is April 3 and the first fall frost is November 21, giving you a growing season of approximately 232 days.
At an elevation of 1,315 feet, Los Angeles County receives approximately 12.9 inches of rainfall annually with predominantly loam soil. Summer highs average 87°F, providing good warmth for Komatsuna during the growing season. With low rainfall, drip irrigation is essential for growing Komatsuna successfully. Mulch heavily to conserve soil moisture.
Los Angeles County Soil Profile
Soil Type
Loam
Soil pH
5.8-7.5
Drainage
Well Drained
Plant Planting Risk Windows
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 Los Angeles County
How your county's soil matches Komatsuna's growing requirements.
Soil pH
Your soil pH (5.8–7.5) overlaps with Komatsuna's range (6.0–7.5), though not a perfect match.
Soil Texture
The loam soil in Los Angeles County is excellent for Komatsuna — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is moderate (2.1%). Annual compost additions will help Komatsuna.
How to Plant Komatsuna
Fall planting: Sow 8 weeks before your first frost date for a fall harvest.
Succession Planting Komatsuna
Sow every 4 weeks. Last sowing by Oct 02 to harvest before frost.
For a dedicated fall crop, sow by Sep 26.
Plant Water Budget
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 | — | 2.4" | 0" | ❄️ Dormant |
| Feb | — | 2.5" | 0" | ❄️ Dormant |
| Mar | — | 2.2" | 0" | ❄️ Dormant |
| Apr | 4.3" | 1.2" | 3.1" | 🚿 Regular watering |
| May | 4.3" | 0.4" | 3.9" | 🚿 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" | 1.3" | 3" | 🚿 Regular watering |
| Dec | — | 2.1" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Nov in Los Angeles 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 Planting Timeline — Los Angeles County, CA
Komatsuna Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | March 6 | Mar 6 – Mar 20 |
| Transplant Outdoors | April 3 | Apr 3 – Apr 17 |
| Direct Sow | March 13 | Mar 13 – Apr 3 |
| Harvest | May 8 | May 8 – Jun 12 |
| Fall Sowing | September 26 | Sep 26 – Oct 10 |
Plant 0.5" deep · 6" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | Start Indoors Direct Sow |
| April | Transplant Outdoors Direct Sow |
| May | Harvest |
| June | Harvest |
| July | — |
| August | — |
| September | Fall Sowing |
| 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 10b
📆 Growing Season
232 days in Los Angeles County
Growing Tips for Komatsuna in Los Angeles County
Direct sow Komatsuna outdoors after April 03 in Los Angeles County when soil has warmed and frost danger has passed.
Your generous 232.0-day season in Los Angeles 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.
Los Angeles 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
Check more plant combinations with our Companion Planting Checker →
Komatsuna in Other Locations
Frequently Asked Questions
When should I plant Komatsuna in Los Angeles County, CA?
Los Angeles County is in Zone 10b with an average last frost of April 3. Plan your Komatsuna planting based on this frost date — see the calendar above for exact timing.
What planting zone is Los Angeles County, CA?
Los Angeles County, California is in USDA Hardiness Zone 10b. The average last spring frost is April 3 and first fall frost is November 21.
Your Los Angeles County Garden Planner — Free
A 24-page printable planner built for Los Angeles County (Zone 10b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.