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When to Plant Parsley in Sheridan County, WY

Parsley is a biennial herb available in flat-leaf (Italian) and curly varieties. It is a nutritional powerhouse rich in vitamins C and K and adds fresh flavor to countless dishes.

Sheridan County, Wyoming is in USDA Zone 4a. The average last spring frost is May 20 and the first fall frost is September 20, giving you a growing season of approximately 123 days.

At an elevation of 5,266 feet, Sheridan County receives approximately 14.7 inches of rainfall annually with predominantly loam soil. Summer highs average 82ยฐF, so choose short-season varieties of Parsley to ensure they mature before fall. With low rainfall, drip irrigation is essential for growing Parsley successfully. Mulch heavily to conserve soil moisture.

Sheridan County, WY (Zone 4a) Short season
123 days
Last Spring Frost May 20
123 growing days
First Fall Frost September 20

Sheridan County Soil Profile

Soil Type

Loam

Soil pH

6.6-7.8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (2 days to spare)
Start indoors: Apr 2 Transplant: May 7 🍅 Harvest: Jul 9 – Sep 10
Recommended (50%) ✓ Fits season (4 days to spare)
Start indoors: Apr 8 Transplant: May 13 🍅 Harvest: Jul 15 – Sep 16
Safe Start (90%) ✗ May not fit
Start indoors: Apr 29 Transplant: Jun 3 🍅 Harvest: Aug 5 – Oct 7

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
1.0″/week
Watering frequency 2-3 times/week
Season total 1,048 gal / 100 sq ft
Drought risk

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

Parsley needs ~805 GDD — county provides 1,414 GDD Excellent fit

Parsley Planting Timeline โ€” Sheridan County, WY

Parsley Planting Calendar

Activity When Date Range
Start Indoors April 8 Apr 8 โ€“ Apr 22
Transplant Outdoors May 13 May 13 โ€“ May 27
Direct Sow May 13 May 13 โ€“ Jun 3
Fall Sowing June 28 Jun 28 โ€“ Jul 12
Harvest July 15 Jul 15 โ€“ Sep 16

Plant 0.5" deep ยท 8" 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 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

60โ€“80 days

Soil pH

6 โ€“ 7

USDA Zone

Zone 4a

Growing Season

123 days

Growing Tips for Sheridan County

Start seeds indoors 6-8 weeks before last frost. Soak seeds overnight as germination is slow. Harvest outer stems first to keep plants productive. Parsley attracts swallowtail butterflies.

Companion Planting

Good Companions

Avoid Planting Near

  • Mint
  • Lettuce

Level Up Your Garden

Frequently Asked Questions

When should I plant Parsley in Sheridan County, WY?

Sheridan County is in Zone 4a with an average last frost of May 20. Plan your Parsley planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Sheridan County, WY?

Sheridan County, Wyoming is in USDA Hardiness Zone 4a. The average last spring frost is May 20 and first fall frost is September 20.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Sheridan County gardeners in Zone 4a 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 Sheridan County, WY. Local conditions may vary. Last updated: April 2026.