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When to plant Spinach in Exeter, CA

For Exeter, gardeners: plant Spinach January 27 through February 17 once soil reads 50°F. A second sowing from October 8 to October 22 extends the harvest into fall.

When to Plant Spinach in Exeter, CA

Spinach
Tulare County, California Zone 9b August

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Avg. last frost February 17
Avg. first frost December 3
Soil temp (4") 76°F
Watering Critical
Pest pressure High
Daylight 13.4 hrs

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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.

Exeter, California is in USDA Zone 9b. The average last spring frost is February 17 and the first fall frost is December 3, giving you a growing season of approximately 289 days.

At an elevation of 5,836 feet, Tulare County receives approximately 18.4 inches of rainfall annually with predominantly loam soil. Summer highs average 95°F, so Spinach may need afternoon shade and extra watering during peak heat. With low rainfall, drip irrigation is essential for growing Spinach successfully. Mulch heavily to conserve soil moisture.

Exeter, CA (Zone 9b) Year-round
289 days
Last Spring Frost February 17
289 growing days
First Fall Frost December 3

Exeter Soil Profile

Soil Type

Loam

Soil pH

5.9-7.2

Drainage

Well Drained

Spinach Planting Risk Windows

Early Start (70% safe) ✓ Fits season (204 days to spare)
Start indoors: Dec 31 Transplant: Jan 28 🍅 Harvest: Mar 4 – May 6
Recommended (50%) ✓ Fits season (191 days to spare)
Start indoors: Jan 20 Transplant: Feb 17 🍅 Harvest: Mar 24 – May 26
Safe Start (90%) ✓ Fits season (165 days to spare)
Start indoors: Mar 6 Transplant: Apr 3 🍅 Harvest: May 8 – Jul 10

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 Exeter

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

Soil pH

Your soil pH (5.9–7.2) overlaps with Spinach's range (6.5–7.5), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is moderate (2.2%). Annual compost additions will help Spinach.

How to Plant Spinach

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

Fall planting: Sow 8 weeks before your first frost date for a fall harvest.

Succession Planting Spinach

10
successive plantings in your 289-day season

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

For a dedicated fall crop, sow by Oct 08.

Spinach Water Budget

Plant needs
0.7″/week
Rainfall provides
0.3″/week
You supply
0.5″/week
Watering frequency 1-2 times/week
Season total 1,343 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 3.6" 0" ❄️ Dormant
Feb 3" 3.7" 0" ✅ Rainfall sufficient
Mar 3" 3" 0" ✅ Rainfall sufficient
Apr 3" 1.5" 1.5" 🚿 Regular watering
May 3" 0.5" 2.5" 🚿 Regular watering
Jun 3" 0.1" 2.9" 🚿 Regular watering
Jul 3" 0" 3" 🚿 Regular watering
Aug 3" 0" 3" 🚿 Regular watering
Sep 3" 0.2" 2.8" 🚿 Regular watering
Oct 3" 0.7" 2.3" 🚿 Regular watering
Nov 3" 1.7" 1.3" 💧 Light watering
Dec 3" 3.4" 0" ✅ Rainfall sufficient

Water needs are for active growing months only (Feb–Dec in Tulare 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 ~903 GDD — county provides 6,162 GDD Excellent fit

Spinach Planting Timeline — Exeter, CA

Spinach Planting Calendar

Activity When Date Range
Start Indoors January 20 Jan 20 – Feb 3
Transplant Outdoors February 17 Feb 17 – Mar 3
Direct Sow January 27 Jan 27 – Feb 17
Harvest March 24 Mar 24 – May 26
Fall Sowing October 8 Oct 8 – Oct 22

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Partial Shade (3-6 hours)

💧 Water

0.7"/week · 1-2 times/week

📅 Days to Maturity

35–50 days

🧪 Soil pH

Needs 6.5–7.5 · Your soil: acceptable

🗺️ USDA Zone

Zone 9b

📆 Growing Season

289 days in Tulare County

Growing Tips for Spinach in Exeter

Direct sow Spinach outdoors after February 17 in Tulare County when soil has warmed and frost danger has passed.

Summer highs in Tulare County reach 95°F — grow Spinach as a spring or fall crop. Use shade cloth if planting in summer.

Your generous 290.0-day season in Tulare 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.

Recommended Spinach Varieties for Exeter

Slow-bolting spinach for warm springs — best as fall crop here

Bloomsdale Long Standing Tyee Space

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.

When should I plant Spinach in Exeter, CA?

In Exeter, CA, plant Spinach after the last frost (around February 17) and before the first frost (around December 3). Best results when soil holds above 50°F.

What growing zone is Exeter, CA for Spinach?

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

Can Spinach grow in Exeter's climate?

Yes — Spinach grows well in Exeter's temperate climate. Exeter averages a 290-day frost-free season, with last frost around February 17 and first frost around December 3.

🌱

Your Tulare County Garden Planner — Free

A 22-page printable planner built for Tulare 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 Tulare County, CA. Local conditions may vary. Last updated: August 2026.