When to Plant Mizuna in Del Norte County, CA
What to do in May
If you only do a handful of things in the garden this May, make it these. They're sequenced around your zone's frost timing.
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Collect mizuna at their peak
Taste as you pick. The first ripe produce is the best feedback loop you'll get all season.
Mizuna is a mild-flavored Japanese mustard green with feathery, deeply serrated leaves. It is fast-growing and makes an excellent addition to salads and stir-fries.
Del Norte County, California is in USDA Zone 9b. The average last spring frost is March 27 and the first fall frost is November 20, giving you a growing season of approximately 238 days.
At an elevation of 72 feet, Del Norte County receives approximately 43.8 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 89°F, providing good warmth for Mizuna during the growing season. Sandy soil warms quickly in spring — great for early planting — but Mizuna will need more frequent watering and organic matter to retain nutrients.
Del Norte County Soil Profile
Soil Type
Sandy Loam
Soil pH
5.9-7
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 Del Norte County
How your county's soil matches Mizuna's growing requirements.
Soil pH
Your soil pH (5.9–7.0) overlaps with Mizuna's range (6.0–7.5), though not a perfect match.
Soil Texture
Sandy soil in Del Norte County warms quickly in spring but drains fast. Mizuna will need more frequent watering and regular compost additions to retain nutrients.
Organic Matter
Organic matter is moderate (2.7%). Annual compost additions will help Mizuna.
How to Plant Mizuna
Fall planting: Sow 8 weeks before your first frost date for a fall harvest.
Succession Planting Mizuna
Sow every 3.4 weeks. Last sowing by Oct 06 to harvest before frost.
For a dedicated fall crop, sow by Sep 25.
Plant Water Budget
Monthly Watering Guide for Mizuna
Mizuna needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.
| Month | Mizuna Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 8.3" | 0" | ❄️ Dormant |
| Feb | — | 9.9" | 0" | ❄️ Dormant |
| Mar | 4.3" | 5.8" | 0" | ✅ Rainfall sufficient |
| Apr | 4.3" | 3.5" | 0.8" | 💧 Light watering |
| May | 4.3" | 1.1" | 3.2" | 🚿 Regular watering |
| Jun | 4.3" | 0.3" | 4" | 🚿 Regular watering |
| Jul | 4.3" | 0" | 4.3" | 🚿 Regular watering |
| Aug | 4.3" | 0" | 4.3" | 🚿 Regular watering |
| Sep | 4.3" | 0.4" | 3.9" | 🚿 Regular watering |
| Oct | 4.3" | 1.9" | 2.4" | 🚿 Regular watering |
| Nov | 4.3" | 4.7" | 0" | ✅ Rainfall sufficient |
| Dec | — | 7.9" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Mar–Nov in Del Norte County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Mizuna 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.
Mizuna Planting Timeline — Del Norte County, CA
Mizuna Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | February 27 | Feb 27 – Mar 13 |
| Transplant Outdoors | March 27 | Mar 27 – Apr 10 |
| Direct Sow | March 6 | Mar 6 – Mar 27 |
| Harvest | May 1 | May 1 – May 29 |
| Fall Sowing | September 25 | Sep 25 – Oct 9 |
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 |
| May | Harvest |
| June | — |
| July | — |
| August | — |
| September | Fall Sowing |
| October | Fall Sowing |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Partial Shade (3-6 hours)
💧 Water
1"/week · Only during dry spells
📅 Days to Maturity
30–45 days
🧪 Soil pH
Needs 6–7.5 · Your soil: acceptable
🗺️ USDA Zone
Zone 9b
📆 Growing Season
238 days in Del Norte County
Growing Tips for Mizuna in Del Norte County
Direct sow Mizuna outdoors after March 27 in Del Norte County when soil has warmed and frost danger has passed.
Sandy soil in Del Norte County dries quickly — mulch Mizuna with 2-3 inches of straw and water deeply 2-3 times per week rather than lightly every day.
Your generous 238.0-day season in Del Norte County allows multiple plantings of Mizuna. Sow every 15.0 days for continuous harvest.
Common pests for Mizuna in this region include cabbage worm and flea beetles. Use row covers early in the season and inspect plants weekly.
General growing tips
Direct sow in spring or fall. Harvest outer leaves as needed for a cut-and-come-again approach. Mizuna is one of the most cold-tolerant Asian greens.
Companion Planting
Good Companions
Avoid Planting Near
Check more plant combinations with our Companion Planting Checker →
Mizuna in Other Locations
Frequently Asked Questions
When should I plant Mizuna in Del Norte County, CA?
Del Norte County is in Zone 9b with an average last frost of March 27. Plan your Mizuna planting based on this frost date — see the calendar above for exact timing.
What planting zone is Del Norte County, CA?
Del Norte County, California is in USDA Hardiness Zone 9b. The average last spring frost is March 27 and first fall frost is November 20.
Your Del Norte County Garden Planner — Free
A 24-page printable planner built for Del Norte 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.