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When to plant Spinach in Lyon County County,

Lyon County County's spring Spinach window runs April 18 through May 9. time plantings around the expected last-frost window for best survival. A second sowing from July 24 to August 7 extends the harvest into fall.

When to Plant Spinach in Lyon County, IA

Spinach
Lyon County, Iowa Zone 5a June

This month in Lyon County, Iowa

June is a pivotal month for Lyon County, Iowa gardens. Focus on these tasks first and you'll set up the rest of the season for success.

Avg. last frost May 2
Avg. first frost October 2
Soil temp (4") 66°F
Watering Low
Pest pressure High
Daylight 15.2 hrs
  1. Start spinach indoors

    You're about 15 weeks out from your last frost — the perfect window to get these germinating indoors.

  2. It's harvest week for spinach

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

July will be here before you know it — start on
  • 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.

Lyon County, Iowa is in USDA Zone 5a. The average last spring frost is May 2 and the first fall frost is October 2, giving you a growing season of approximately 153 days.

At an elevation of 1,045 feet, Lyon County receives approximately 30.4 inches of rainfall annually with predominantly silt loam soil. Summer highs average 80°F, so choose short-season varieties of Spinach to ensure they mature before fall.

Lyon County, IA (Zone 5a) Moderate season
153 days
Last Spring Frost May 2
153 growing days
First Fall Frost October 2

Lyon County Soil Profile

Soil Type

Silt Loam

Soil pH

6.3-6.8

Drainage

Well Drained

Spinach Planting Risk Windows

Early Start (70% safe) ✓ Fits season (53 days to spare)
Start indoors: Mar 23 Transplant: Apr 27 🍅 Harvest: Jun 1 – Aug 3
Recommended (50%) ✓ Fits season (55 days to spare)
Start indoors: Mar 28 Transplant: May 2 🍅 Harvest: Jun 6 – Aug 8
Safe Start (90%) ✓ Fits season (52 days to spare)
Start indoors: Apr 11 Transplant: May 16 🍅 Harvest: Jun 20 – Aug 22

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 Lyon County

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

Soil pH

Your soil pH (6.3–6.8) overlaps with Spinach's range (6.5–7.5), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is excellent (4.6%) — 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

5
successive plantings in your 153-day season

Sow every 4 weeks. Last sowing by Aug 13 to harvest before frost.

For a dedicated fall crop, sow by Jul 24.

Spinach Water Budget

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

Water stress score is 6/10 — 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 1.4" 0" ❄️ Dormant
Feb 1.5" 0" ❄️ Dormant
Mar 2" 0" ❄️ Dormant
Apr 3.2" 0" ❄️ Dormant
May 3" 3" 0" ✅ Rainfall sufficient
Jun 3" 4.2" 0" ✅ Rainfall sufficient
Jul 3" 3.7" 0" ✅ Rainfall sufficient
Aug 3" 2.7" 0.3" 💧 Light watering
Sep 3" 2.3" 0.7" 💧 Light watering
Oct 3" 2.5" 0.5" 💧 Light watering
Nov 2.1" 0" ❄️ Dormant
Dec 1.8" 0" ❄️ Dormant

Water needs are for active growing months only (May–Oct in Lyon 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 ~425 GDD — county provides 1,530 GDD Excellent fit

Spinach Planting Timeline — Lyon County, IA

Spinach Planting Calendar

Activity When Date Range
Start Indoors March 28 Mar 28 – Apr 11
Transplant Outdoors May 2 May 2 – May 16
Direct Sow April 18 Apr 18 – May 9
Harvest June 6 Jun 6 – Aug 8
Fall Sowing July 24 Jul 24 – Aug 7

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

Month-by-Month Timeline

MonthActivities
January
February
March Start Indoors
April Start Indoors Direct Sow
May Transplant Outdoors Direct Sow
June 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 5a

📆 Growing Season

153 days in Lyon County

Growing Tips for Spinach in Lyon County

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

Your generous 153.0-day season in Lyon 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 Lyon County, IA?

Lyon County is in Zone 5a with an average last frost of May 2. Plan your Spinach planting based on this frost date — see the calendar above for exact timing.

What planting zone is Lyon County, IA?

Lyon County, Iowa is in USDA Hardiness Zone 5a. The average last spring frost is May 2 and first fall frost is October 2.

When should I plant Spinach in Lyon County, ?

In Lyon County, , plant Spinach after the last frost (around May 2) and before the first frost (around October 2). Best results when soil holds above 50°F.

What growing zone is Lyon County, for Spinach?

Lyon County sits in USDA Zone 5a. Spinach grows reliably in zones 2a through 10b, so it's a good fit here.

Can Spinach grow in Lyon County's climate?

Yes — Spinach grows well in Lyon County's temperate climate. Lyon County averages a 153-day frost-free season, with last frost around May 2 and first frost around October 2.

🌱

Your Lyon County Garden Planner — Free

A 22-page printable planner built for Lyon County (Zone 5a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

Instant PDF download. No spam, unsubscribe any time.

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Lyon County, IA. 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.