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When to Plant Spinach in Park County, WY

Spinach

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.

Park County, Wyoming is in USDA Zone 5a. The average last spring frost is May 21 and the first fall frost is September 22, giving you a growing season of approximately 124 days.

At an elevation of 6,993 feet, Park County receives approximately 16.7 inches of rainfall annually with predominantly loam soil. Summer highs average 83°F, so choose short-season varieties of Spinach to ensure they mature before fall. With low rainfall, drip irrigation is essential for growing Spinach successfully. Mulch heavily to conserve soil moisture.

Park County, WY (Zone 5a) Short season
124 days
Last Spring Frost May 21
124 growing days
First Fall Frost September 22

Park County Soil Profile

Soil Type

Loam

Soil pH

6.8-8.2

Drainage

Well Drained

Monthly Watering Guide for Spinach

Spinach needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.

Month Spinach Needs Rainfall You Supplement Action
Jan 1.3" 0" ❄️ Dormant
Feb 0.9" 0" ❄️ Dormant
Mar 1.3" 0" ❄️ Dormant
Apr 1.8" 0" ❄️ Dormant
May 4.3" 2.1" 2.2" 🚿 Regular watering
Jun 4.3" 1.2" 3.1" 🚿 Regular watering
Jul 4.3" 1.5" 2.8" 🚿 Regular watering
Aug 4.3" 1.7" 2.6" 🚿 Regular watering
Sep 4.3" 1.2" 3.1" 🚿 Regular watering
Oct 1.4" 0" ❄️ Dormant
Nov 1.3" 0" ❄️ Dormant
Dec 1" 0" ❄️ Dormant

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

Spinach Planting Timeline — Park County, WY

Spinach Planting Calendar

Activity When Date Range
Start Indoors April 16 Apr 16 – Apr 30
Transplant Outdoors May 21 May 21 – Jun 4
Direct Sow May 7 May 7 – May 28
Harvest June 25 Jun 25 – Aug 27
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
May Transplant Outdoors Direct Sow
June Transplant Outdoors Harvest
July Fall Sowing Harvest
August Harvest
September
October
November
December

Growing Conditions

☀️ Sun

Partial Shade (3-6 hours)

💧 Water

Moderate — regular watering

📅 Days to Maturity

35–50 days

🧪 Soil pH

Needs 6.5–7.5 · Your soil: N/A

🗺️ USDA Zone

Zone 5a

📆 Growing Season

124 days in Park County

Growing Tips for Park County

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 Park County, WY?

Park County is in Zone 5a with an average last frost of May 21. Plan your Spinach planting based on this frost date — see the calendar above for exact timing.

What planting zone is Park County, WY?

Park County, Wyoming is in USDA Hardiness Zone 5a. The average last spring frost is May 21 and first fall frost is September 22.

🌱

Your Park County Garden Planner — Free

A 22-page printable planner built for Park 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 Park County, WY. Local conditions may vary. Last updated: July 2026.

Sources & credits

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