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When to Plant Spinach in Wallowa County, OR

Wallowa County, Oregon Zone 6b May

This month in Wallowa County, Oregon

Here's what deserves your attention in Wallowa County, Oregon this month. Everything below is tailored to Zone 6b and timed around your local frost dates.

Avg. last frost May 11
Avg. first frost September 22
Soil temp (4") 57°F
Watering High
Pest pressure Low
Daylight 14.7 hrs
  1. Harden off and plant spinach

    Plant tomatoes deep — bury the stem up to the first true leaves to grow extra roots. Everything else goes in at the same depth it grew in the tray.

Get ahead of June
  • Starting indoors: spinach
  • 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.

Wallowa County, Oregon is in USDA Zone 6b. The average last spring frost is May 11 and the first fall frost is September 22, giving you a growing season of approximately 134 days.

At an elevation of 1,240 feet, Wallowa County receives approximately 22.6 inches of rainfall annually with predominantly silt loam soil. Summer highs average 85°F, providing good warmth for Spinach during the growing season.

Wallowa County, OR (Zone 6b) Short season
134 days
Last Spring Frost May 11
134 growing days
First Fall Frost September 22

Wallowa County Soil Profile

Soil Type

Silt Loam

Soil pH

5.3-6.2

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (34 days to spare)
Start indoors: Mar 27 Transplant: May 1 🍅 Harvest: Jun 5 – Aug 7
Recommended (50%) ✓ Fits season (36 days to spare)
Start indoors: Apr 6 Transplant: May 11 🍅 Harvest: Jun 15 – Aug 17
Safe Start (90%) ✓ Fits season (41 days to spare)
Start indoors: May 8 Transplant: Jun 12 🍅 Harvest: Jul 17 – Sep 18

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 Wallowa County

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

Soil pH

Your soil pH (5.3–6.2) is more acidic than Spinach prefers (6.5–7.5). Add garden lime to raise pH.

Soil Texture

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

Drainage

Drainage is adequate for Spinach.

Organic Matter

Organic matter is excellent (5.4%) — Spinach will thrive.

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 134-day season

Sow every 4 weeks. Last sowing by Aug 03 to harvest before frost.

For a dedicated fall crop, sow by Jul 14.

Plant Water Budget

Plant needs
0.7″/week
Rainfall provides
0.7″/week
You supply
0.2″/week
Watering frequency Only during dry spells
Season total 240 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 2.9" 0" ❄️ Dormant
Feb 2.3" 0" ❄️ Dormant
Mar 2.1" 0" ❄️ Dormant
Apr 1.5" 0" ❄️ Dormant
May 3" 1.3" 1.7" 🚿 Regular watering
Jun 3" 1" 2" 🚿 Regular watering
Jul 3" 0.4" 2.6" 🚿 Regular watering
Aug 3" 0.4" 2.6" 🚿 Regular watering
Sep 3" 1" 2" 🚿 Regular watering
Oct 2.1" 0" ❄️ Dormant
Nov 3.9" 0" ❄️ Dormant
Dec 3.6" 0" ❄️ Dormant

Water needs are for active growing months only (May–Sep in Wallowa 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 ~584 GDD — county provides 1,842 GDD Excellent fit

Spinach Planting Timeline — Wallowa County, OR

Spinach Planting Calendar

Activity When Date Range
Start Indoors April 6 Apr 6 – Apr 20
Transplant Outdoors May 11 May 11 – May 25
Direct Sow April 27 Apr 27 – May 18
Harvest June 15 Jun 15 – Aug 17
Fall Sowing July 14 Jul 14 – Jul 28

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Partial Shade (3-6 hours)

💧 Water

0.7"/week · Only during dry spells

📅 Days to Maturity

35–50 days

🧪 Soil pH

Needs 6.5–7.5 · Your soil: too_acidic

🗺️ USDA Zone

Zone 6b

📆 Growing Season

134 days in Wallowa County

Growing Tips for Spinach in Wallowa County

Direct sow Spinach outdoors after May 11 in Wallowa County when soil has warmed and frost danger has passed.

Your generous 134.0-day season in Wallowa 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 Wallowa 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 Wallowa County, OR?

Wallowa County is in Zone 6b with an average last frost of May 11. Plan your Spinach planting based on this frost date — see the calendar above for exact timing.

What planting zone is Wallowa County, OR?

Wallowa County, Oregon is in USDA Hardiness Zone 6b. The average last spring frost is May 11 and first fall frost is September 22.

🌱

Your Wallowa County Garden Planner — Free

A 24-page printable planner built for Wallowa 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 Wallowa County, OR. 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.