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When to Plant Mizuna in Del Norte County, CA

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 8b. 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 89ยฐF, providing good warmth for Mizuna during the growing season. Sandy soil warms quickly in spring โ€” great for early planting โ€” but Mizuna will need more frequent watering and organic matter to retain nutrients.

Del Norte County, CA (Zone 8b) Long season
238 days
Last Spring Frost March 27
238 growing days
First Fall Frost November 20

Del Norte County Soil Profile

Soil Type

Sandy Loam

Soil pH

5.9-7

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (174 days to spare)
Start indoors: Jan 29 Transplant: Mar 5 🍅 Harvest: Apr 9 – May 7
Recommended (50%) ✓ Fits season (175 days to spare)
Start indoors: Feb 20 Transplant: Mar 27 🍅 Harvest: May 1 – May 29
Safe Start (90%) ✓ Fits season (164 days to spare)
Start indoors: Mar 30 Transplant: May 4 🍅 Harvest: Jun 8 – 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.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.8″/week
You supply
0.2″/week
Watering frequency Only during dry spells
Season total 481 gal / 100 sq ft
Mizuna needs ~628 GDD — county provides 3,986 GDD Excellent fit

Mizuna Planting Timeline โ€” Del Norte County, CA

Mizuna Planting Calendar

Activity When Date Range
Start Indoors February 20 Feb 20 โ€“ Mar 6
Transplant Outdoors March 27 Mar 27 โ€“ Apr 10
Direct Sow March 13 Mar 13 โ€“ Apr 3
Fall Sowing September 11 Sep 11 โ€“ Sep 25
Harvest May 1 May 1 โ€“ May 29

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

Month-by-Month Timeline

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

Growing Conditions

Sun

Partial Shade (3-6 hours)

Water

Moderate โ€” regular watering

Days to Maturity

30โ€“45 days

Soil pH

6 โ€“ 7.5

USDA Zone

Zone 8b

Growing Season

238 days

Growing Tips for Del Norte County

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

  • Strawberries

Level Up Your Garden

Frequently Asked Questions

When should I plant Mizuna in Del Norte County, CA?

Del Norte County is in Zone 8b with an average last frost of March 27. Plan your Mizuna planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Del Norte County, CA?

Del Norte County, California is in USDA Hardiness Zone 8b. The average last spring frost is March 27 and first fall frost is November 20.

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Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Del Norte County gardeners in Zone 8b organize planting dates, track what's growing, and never miss a planting window.

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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 Del Norte County, CA. Local conditions may vary. Last updated: April 2026.