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When to plant Spinach in Mariposa County, CA

In Mariposa County, plant Spinach in spring between March 28 and April 18, once soil temps hold above 50°F. Mariposa County's last frost averages April 18, so aim for a steady week of warm soil before planting. For a fall crop, sow between September 14 and September 28 — roughly 35–50 days before the first frost on November 9.

When to Plant Spinach in Mariposa County, CA

Spinach

Spinach is a nutrient-packed cool-season green that grows quickly in spring and fall. It is rich in iron, vitamins, and antioxidants and excellent raw or cooked.

Mariposa County, California is in USDA Zone 9b. The average last spring frost is April 18 and the first fall frost is November 9, giving you a growing season of approximately 205 days.

At an elevation of 192 feet, Mariposa County receives approximately 19.2 inches of rainfall annually with predominantly loam soil. Summer highs average 91°F, providing good warmth for Spinach during the growing season. With low rainfall, drip irrigation is essential for growing Spinach successfully. Mulch heavily to conserve soil moisture.

Mariposa County, CA (Zone 9b) Long season
205 days
Last Spring Frost April 18
205 growing days
First Fall Frost November 9

Mariposa County Soil Profile

Soil Type

Loam

Soil pH

6.0-7.0

Drainage

Well Drained

Spinach Planting Timeline — Mariposa County, CA

Spinach Planting Calendar

Activity When Date Range
Start Indoors March 21 Mar 21 – Apr 4
Transplant Outdoors April 18 Apr 18 – May 2
Direct Sow March 28 Mar 28 – Apr 18
Harvest May 23 May 23 – Jul 25
Fall Sowing September 14 Sep 14 – Sep 28

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

Month-by-Month Timeline

MonthActivities
January
February
March Start Indoors Direct Sow
April Start Indoors Transplant Outdoors Direct Sow
May Transplant Outdoors Harvest
June Harvest
July Harvest
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 6.5–7.5 · Your soil: N/A

🗺️ USDA Zone

Zone 9b

📆 Growing Season

205 days in Mariposa County

Growing Tips for Mariposa County

Direct sow as soon as soil can be worked in spring. Plant in partial shade for summer crops to delay bolting. Succession plant every 2 weeks for continuous harvest.

Companion Planting

Good Companions

Check more plant combinations with our Companion Planting Checker →

🌾 Save Your Own Spinach Seeds
Life Cycle Annual
Pollination Wind Pollinated
How to Collect Let plants bolt. Harvest seed stalks when seeds turn tan.
Storage Store airtight; viable 5 years at 35°F, under 45% humidity.

Wind pollinated — isolate 1/2 mile for purity. Easy to let bolt in heat.

Frequently Asked Questions

When should I plant Spinach in Mariposa County, CA?

Mariposa County is in Zone 9b with an average last frost of April 18. Plan your Spinach planting based on this frost date — see the calendar above for exact timing.

What planting zone is Mariposa County, CA?

Mariposa County, California is in USDA Hardiness Zone 9b. The average last spring frost is April 18 and first fall frost is November 9.

When should I plant Spinach in Mariposa County, CA?

In Mariposa County, CA, plant Spinach after the last frost (around April 18) and before the first frost (around November 9). Best results when soil holds above 50°F.

What growing zone is Mariposa County, CA for Spinach?

Mariposa County sits in USDA Zone 9b. Spinach grows reliably in zones 2a through 10b, so it's a good fit here.

Can Spinach grow in Mariposa County's climate?

Yes — Spinach grows well in Mariposa County's temperate climate. Mariposa County averages a 205-day frost-free season, with last frost around April 18 and first frost around November 9.

🌱

Your Mariposa County Garden Planner — Free

A 22-page printable planner built for Mariposa 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.

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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 Mariposa County, CA. Local conditions may vary. Last updated: July 2026.

Sources & credits

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