When to Plant Komatsuna in Mendocino County, CA
Your May planting checklist for Mendocino County, California
Your Mendocino 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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Bring in the komatsuna
Morning harvests are best — cooler temperatures mean crisper produce and longer fridge life.
June will be here before you know it — start on
- 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.
Mendocino County, California is in USDA Zone 9b. The average last spring frost is March 23 and the first fall frost is November 9, giving you a growing season of approximately 231 days.
At an elevation of 180 feet, Mendocino County receives approximately 24 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 87°F, providing good warmth for Komatsuna during the growing season. Sandy soil warms quickly in spring — great for early planting — but Komatsuna will need more frequent watering and organic matter to retain nutrients.
Mendocino County Soil Profile
Soil Type
Sandy Loam
Soil pH
6.1-7.2
Drainage
Well Drained
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 | — | 5.2" | 0" | ❄️ Dormant |
| Feb | — | 4.6" | 0" | ❄️ Dormant |
| Mar | 4.3" | 3.7" | 0.6" | 💧 Light watering |
| Apr | 4.3" | 1.9" | 2.4" | 🚿 Regular watering |
| May | 4.3" | 0.6" | 3.7" | 🚿 Regular watering |
| Jun | 4.3" | 0.2" | 4.1" | 🚿 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" | 1" | 3.3" | 🚿 Regular watering |
| Nov | 4.3" | 2.6" | 1.7" | 💧 Light watering |
| Dec | — | 3.9" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Mar–Nov in Mendocino County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Komatsuna Planting Timeline — Mendocino County, CA
Komatsuna Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | February 23 | Feb 23 – Mar 9 |
| Transplant Outdoors | March 23 | Mar 23 – Apr 6 |
| Direct Sow | March 2 | Mar 2 – Mar 23 |
| Harvest | April 27 | Apr 27 – Jun 1 |
| Fall Sowing | September 14 | Sep 14 – Sep 28 |
Plant 0.5" deep · 6" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | Start Indoors |
| March | Start Indoors Transplant Outdoors Direct Sow |
| April | Transplant Outdoors Harvest |
| May | Harvest |
| June | Harvest |
| July | — |
| August | — |
| September | Fall Sowing |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Partial Shade (3-6 hours)
💧 Water
Moderate — regular watering
📅 Days to Maturity
35–50 days
🧪 Soil pH
Needs 6–7.5 · Your soil: N/A
🗺️ USDA Zone
Zone 9b
📆 Growing Season
231 days in Mendocino County
Growing Tips for Mendocino County
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 Mendocino County, CA?
Mendocino County is in Zone 9b with an average last frost of March 23. Plan your Komatsuna planting based on this frost date — see the calendar above for exact timing.
What planting zone is Mendocino County, CA?
Mendocino County, California is in USDA Hardiness Zone 9b. The average last spring frost is March 23 and first fall frost is November 9.
Your Mendocino County Garden Planner — Free
A 24-page printable planner built for Mendocino 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.