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When to plant Spinach in Alpine County, CA

Alpine County's climate puts the Spinach spring window between May 5 and May 26. time plantings around the expected last-frost window for best survival. A second sowing from July 25 to August 8 extends the harvest into fall.

When to Plant Spinach in Alpine County, CA

Spinach
Alpine County, California Zone 6b June

June to-do list for Alpine County, California

If you only do a handful of things in the garden this June, make it these. They're sequenced around your zone's frost timing.

Avg. last frost May 19
Avg. first frost October 3
Soil temp (4") 69°F
Watering Critical
Pest pressure High
Daylight 14.7 hrs
  1. Time to start spinach inside

    Label every cell. You will absolutely forget which is which otherwise.

  2. Basket week: spinach

    Morning harvests are best — cooler temperatures mean crisper produce and longer fridge life.

Before July arrives, get these ready
  • First harvests: spinach
  • Fall sowing: spinach

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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.

Alpine County, California is in USDA Zone 6b. The average last spring frost is May 19 and the first fall frost is October 3, giving you a growing season of approximately 137 days.

At an elevation of 1,278 feet, Alpine County receives approximately 36.3 inches of rainfall annually with predominantly loam soil. Summer highs average 84°F, so choose short-season varieties of Spinach to ensure they mature before fall.

Alpine County, CA (Zone 6b) Short season
137 days
Last Spring Frost May 19
137 growing days
First Fall Frost October 3

Alpine County Soil Profile

Soil Type

Loam

Soil pH

6.4-7.3

Drainage

Well Drained

Spinach Planting Risk Windows

Early Start (70% safe) ✓ Fits season (46 days to spare)
Start indoors: Mar 29 Transplant: May 3 🍅 Harvest: Jun 7 – Aug 9
Recommended (50%) ✓ Fits season (39 days to spare)
Start indoors: Apr 14 Transplant: May 19 🍅 Harvest: Jun 23 – Aug 25
Safe Start (90%) ✓ Fits season (34 days to spare)
Start indoors: May 6 Transplant: Jun 10 🍅 Harvest: Jul 15 – Sep 16

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 Alpine County

How your county's soil matches Spinach's growing requirements.

Soil pH

Your soil pH (6.4–7.3) overlaps with Spinach's range (6.5–7.5), though not a perfect match.

Soil Texture

The loam soil in Alpine County is excellent for Spinach — good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is moderate (3.2%). Annual compost additions will help Spinach.

How to Plant Spinach

0.5"
Planting Depth
6"
Between Plants
12"
Between Rows

Fall planting: Sow 10 weeks before your first frost date for a fall harvest.

Succession Planting Spinach

4
successive plantings in your 137-day season

Sow every 4 weeks. Last sowing by Aug 14 to harvest before frost.

For a dedicated fall crop, sow by Jul 25.

Spinach Water Budget

Plant needs
0.7″/week
Rainfall provides
1.1″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft
Drought risk

Water stress score is 8/10 — consider drought-tolerant varieties and mulching

Monthly Watering Guide for Spinach

Spinach needs approximately 0.7 inches of water per week (3" per month). Here's how your county's rainfall compares month by month.

Month Spinach Needs Rainfall You Supplement Action
Jan 7.1" 0" ❄️ Dormant
Feb 8.7" 0" ❄️ Dormant
Mar 5.7" 0" ❄️ Dormant
Apr 2.7" 0" ❄️ Dormant
May 3" 1" 2" 🚿 Regular watering
Jun 3" 0.2" 2.8" 🚿 Regular watering
Jul 3" 0" 3" 🚿 Regular watering
Aug 3" 0" 3" 🚿 Regular watering
Sep 3" 0.3" 2.7" 🚿 Regular watering
Oct 3" 1.6" 1.4" 💧 Light watering
Nov 3.7" 0" ❄️ Dormant
Dec 5.3" 0" ❄️ Dormant

Water needs are for active growing months only (May–Oct in Alpine County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.

Spinach 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.

Spinach needs ~552 GDD — county provides 1,781 GDD Excellent fit

Spinach Planting Timeline — Alpine County, CA

Spinach Planting Calendar

Activity When Date Range
Start Indoors April 14 Apr 14 – Apr 28
Transplant Outdoors May 19 May 19 – Jun 2
Direct Sow May 5 May 5 – May 26
Harvest June 23 Jun 23 – Aug 25
Fall Sowing July 25 Jul 25 – Aug 8

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Partial Shade (3-6 hours)

💧 Water

0.7"/week · Natural rainfall sufficient

📅 Days to Maturity

35–50 days

🧪 Soil pH

Needs 6.5–7.5 · Your soil: acceptable

🗺️ USDA Zone

Zone 6b

📆 Growing Season

137 days in Alpine County

Growing Tips for Spinach in Alpine County

Direct sow Spinach outdoors after May 19 in Alpine County when soil has warmed and frost danger has passed.

Your generous 137.0-day season in Alpine County allows multiple plantings of Spinach. Sow every 17.0 days for continuous harvest.

General growing tips

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 Alpine County, CA?

Alpine County is in Zone 6b with an average last frost of May 19. Plan your Spinach planting based on this frost date — see the calendar above for exact timing.

What planting zone is Alpine County, CA?

Alpine County, California is in USDA Hardiness Zone 6b. The average last spring frost is May 19 and first fall frost is October 3.

When should I plant Spinach in Alpine County, CA?

In Alpine County, CA, plant Spinach after the last frost (around May 19) and before the first frost (around October 3). Best results when soil holds above 50°F.

What growing zone is Alpine County, CA for Spinach?

Alpine County sits in USDA Zone 6b. Spinach grows reliably in zones 2a through 10b, so it's a good fit here.

Can Spinach grow in Alpine County's climate?

Yes — Spinach grows well in Alpine County's temperate climate. Alpine County averages a 137-day frost-free season, with last frost around May 19 and first frost around October 3.

🌱

Your Alpine County Garden Planner — Free

A 22-page printable planner built for Alpine County (Zone 6b). 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 Alpine County, CA. Local conditions may vary. Last updated: June 2026.

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.