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When to Plant Spinach in Washington County, TX

Washington County, Texas Zone 9a May

Your May gardening checklist

Welcome to May in Zone 9a. These are the moves that will have the biggest impact on your growing season.

Avg. last frost March 2
Avg. first frost November 27
Soil temp (4") 71°F
Watering Low
Pest pressure High
Daylight 13.5 hrs
  1. Harvest spinach as they ripen

    The more you pick, the more the plant produces. Letting fruit overripen tells the plant it's time to stop.

A few tasks this May that'll pay off in June
  • First harvests: 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.

Washington County, Texas is in USDA Zone 9a. The average last spring frost is March 2 and the first fall frost is November 27, giving you a growing season of approximately 270 days.

At an elevation of 386 feet, Washington County receives approximately 58.9 inches of rainfall annually with predominantly clay soil. Summer highs average 90°F, providing good warmth for Spinach during the growing season. Clay soil retains moisture well for Spinach, but amend with compost to improve drainage and prevent root rot. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Spinach root diseases.

Washington County, TX (Zone 9a) Year-round
270 days
Last Spring Frost March 2
270 growing days
First Fall Frost November 27
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Washington County Soil Profile

Soil Type

Clay

Soil pH

6.9-8.4

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (175 days to spare)
Start indoors: Jan 18 Transplant: Feb 15 🍅 Harvest: Mar 22 – May 24
Recommended (50%) ✓ Fits season (172 days to spare)
Start indoors: Feb 2 Transplant: Mar 2 🍅 Harvest: Apr 6 – Jun 8
Safe Start (90%) ✓ Fits season (173 days to spare)
Start indoors: Feb 22 Transplant: Mar 22 🍅 Harvest: Apr 26 – Jun 28

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 Washington County

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

Soil pH

Your soil pH (6.9–8.4) is more alkaline than Spinach prefers (6.5–7.5). Add sulfur or peat moss to lower pH.

Soil Texture

Your clay soil in Washington County is workable for Spinach. Add compost annually to improve structure.

Organic Matter

Organic matter is moderate (2.6%). 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

9
successive plantings in your 270-day season

Sow every 4 weeks. Last sowing by Oct 08 to harvest before frost.

For a dedicated fall crop, sow by Oct 02.

Plant Water Budget

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

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 1.6" 0" ❄️ Dormant
Feb 1.9" 0" ❄️ Dormant
Mar 3" 4.3" 0" ✅ Rainfall sufficient
Apr 3" 5.8" 0" ✅ Rainfall sufficient
May 3" 8.3" 0" ✅ Rainfall sufficient
Jun 3" 9.9" 0" ✅ Rainfall sufficient
Jul 3" 7" 0" ✅ Rainfall sufficient
Aug 3" 7.4" 0" ✅ Rainfall sufficient
Sep 3" 5.2" 0" ✅ Rainfall sufficient
Oct 3" 4.2" 0" ✅ Rainfall sufficient
Nov 3" 2" 1" 💧 Light watering
Dec 1.4" 0" ❄️ Dormant

Water needs are for active growing months only (Mar–Nov in Washington 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 ~744 GDD — county provides 4,725 GDD Excellent fit

Spinach Planting Timeline — Washington County, TX

Spinach Planting Calendar

Activity When Date Range
Start Indoors February 2 Feb 2 – Feb 16
Transplant Outdoors March 2 Mar 2 – Mar 16
Direct Sow February 9 Feb 9 – Mar 2
Harvest April 6 Apr 6 – Jun 8
Fall Sowing October 2 Oct 2 – Oct 16

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

Month-by-Month Timeline

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

🗺️ USDA Zone

Zone 9a

📆 Growing Season

270 days in Washington County

Growing Tips for Spinach in Washington County

Direct sow Spinach outdoors after March 02 in Washington County when soil has warmed and frost danger has passed.

With Washington County's clay soil (37% clay), work in 3-4 inches of compost before planting Spinach. Avoid tilling when soil is wet to prevent compaction.

Your generous 270.0-day season in Washington 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 Washington County

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.

Frequently Asked Questions

When should I plant Spinach in Washington County, TX?

Washington County is in Zone 9a with an average last frost of March 2. Plan your Spinach planting based on this frost date — see the calendar above for exact timing.

What planting zone is Washington County, TX?

Washington County, Texas is in USDA Hardiness Zone 9a. The average last spring frost is March 2 and first fall frost is November 27.

🌱

Your Washington County Garden Planner — Free

A 24-page printable planner built for Washington County (Zone 9a). 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 Washington County, TX. Local conditions may vary. Last updated: May 2026.

Sources & credits

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