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When to Plant Arugula in Natrona County, WY

Arugula is a fast-growing cool-season green with a peppery, nutty flavor. It is excellent in salads and can be harvested as baby greens or mature leaves.

Natrona County, Wyoming is in USDA Zone 4b. The average last spring frost is May 19 and the first fall frost is September 23, giving you a growing season of approximately 127 days.

At an elevation of 6,332 feet, Natrona County receives approximately 13.7 inches of rainfall annually with predominantly loam soil. Summer highs average 83ยฐF, so choose short-season varieties of Arugula to ensure they mature before fall. With low rainfall, drip irrigation is essential for growing Arugula successfully. Mulch heavily to conserve soil moisture.

Natrona County, WY (Zone 4b) Short season
127 days
Last Spring Frost May 19
127 growing days
First Fall Frost September 23

Natrona County Soil Profile

Soil Type

Loam

Soil pH

6.5-7.6

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (30 days to spare)
Start indoors: Mar 31 Transplant: May 12 🍅 Harvest: Jun 16 – Aug 18
Recommended (50%) ✓ Fits season (29 days to spare)
Start indoors: Apr 7 Transplant: May 19 🍅 Harvest: Jun 23 – Aug 25
Safe Start (90%) ✓ Fits season (31 days to spare)
Start indoors: Apr 21 Transplant: Jun 2 🍅 Harvest: Jul 7 – Sep 8

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
0.5″/week
You supply
0.7″/week
Watering frequency 1-2 times/week
Season total 742 gal / 100 sq ft
Drought risk

Water stress score is 8/10 โ€” consider drought-tolerant varieties and mulching

Arugula needs ~490 GDD — county provides 1,555 GDD Excellent fit

Arugula Planting Timeline โ€” Natrona County, WY

Arugula Planting Calendar

Activity When Date Range
Start Indoors April 7 Apr 7 โ€“ Apr 21
Transplant Outdoors May 19 May 19 โ€“ Jun 2
Direct Sow May 12 May 12 โ€“ Jun 2
Fall Sowing July 1 Jul 1 โ€“ Jul 15
Harvest June 23 Jun 23 โ€“ Aug 25

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 Transplant Outdoors Direct Sow
June Transplant Outdoors Direct Sow Harvest
July Fall Sowing Harvest
August Harvest
September โ€”
October โ€”
November โ€”
December โ€”

Growing Conditions

Sun

Partial Shade (3-6 hours)

Water

Moderate โ€” regular watering

Days to Maturity

30โ€“50 days

Soil pH

6 โ€“ 7

USDA Zone

Zone 4b

Growing Season

127 days

Growing Tips for Natrona County

Sow seeds directly every 2-3 weeks for continuous harvest. Provide afternoon shade in warm weather to prevent bolting. Harvest outer leaves first to extend production.

Companion Planting

Good Companions

Avoid Planting Near

  • Strawberries

Level Up Your Garden

Frequently Asked Questions

When should I plant Arugula in Natrona County, WY?

Natrona County is in Zone 4b with an average last frost of May 19. Plan your Arugula planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Natrona County, WY?

Natrona County, Wyoming is in USDA Hardiness Zone 4b. The average last spring frost is May 19 and first fall frost is September 23.

๐ŸŒฑ

Plan Your Garden with Confidence

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

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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 Natrona County, WY. Local conditions may vary. Last updated: April 2026.