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When to Plant Spinach in Rich County, UT

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.

Rich County, Utah is in USDA Zone 4b. The average last spring frost is May 31 and the first fall frost is September 15, giving you a growing season of approximately 107 days.

At an elevation of 5,803 feet, Rich County receives approximately 18 inches of rainfall annually with predominantly loam soil. Summer highs average 81ยฐF, 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.

Rich County, UT (Zone 4b) Short season
107 days
Last Spring Frost May 31
107 growing days
First Fall Frost September 15

Rich County Soil Profile

Soil Type

Loam

Soil pH

6.5-8.2

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (12 days to spare)
Start indoors: Apr 2 Transplant: May 14 🍅 Harvest: Jun 18 – Aug 20
Recommended (50%) ✓ Fits season (9 days to spare)
Start indoors: Apr 19 Transplant: May 31 🍅 Harvest: Jul 5 – Sep 6
Safe Start (90%) ✓ Fits season (21 days to spare)
Start indoors: May 11 Transplant: Jun 22 🍅 Harvest: Jul 27 – Sep 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.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.7″/week
You supply
0.4″/week
Watering frequency 1-2 times/week
Season total 335 gal / 100 sq ft
Drought risk

Water stress score is 10/10 โ€” consider drought-tolerant varieties and mulching

Spinach needs ~457 GDD — county provides 1,150 GDD Excellent fit

Spinach Planting Timeline โ€” Rich County, UT

Spinach Planting Calendar

Activity When Date Range
Start Indoors April 19 Apr 19 โ€“ May 3
Transplant Outdoors May 31 May 31 โ€“ Jun 14
Direct Sow May 24 May 24 โ€“ Jun 14
Fall Sowing June 23 Jun 23 โ€“ Jul 7
Harvest July 5 Jul 5 โ€“ Sep 6

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

Month-by-Month Timeline

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

Growing Conditions

Sun

Partial Shade (3-6 hours)

Water

Moderate โ€” regular watering

Days to Maturity

35โ€“50 days

Soil pH

6.5 โ€“ 7.5

USDA Zone

Zone 4b

Growing Season

107 days

Growing Tips for Rich 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

Level Up Your Garden

๐ŸŒพ 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 35ยฐF, under 45% humidity.

Wind pollinated โ€” isolate 1/2 mile for purity. Easy to let bolt in heat.

Frequently Asked Questions

When should I plant Spinach in Rich County, UT?

Rich County is in Zone 4b with an average last frost of May 31. Plan your Spinach planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Rich County, UT?

Rich County, Utah is in USDA Hardiness Zone 4b. The average last spring frost is May 31 and first fall frost is September 15.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Rich County gardeners in Zone 4b organize planting dates, track what's growing, and never miss a planting window.

Get Your Free Garden Planner →

Free download. Plan your entire garden season in minutes.

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Rich County, UT. Local conditions may vary. Last updated: April 2026.