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When to Plant Scallions in Hot Springs County, WY

Scallions (green onions) are mild-flavored alliums harvested for their slender green tops and white bases. They are quick-growing and perfect for succession planting.

Hot Springs County, Wyoming is in USDA Zone 4b. The average last spring frost is May 11 and the first fall frost is October 2, giving you a growing season of approximately 144 days.

At an elevation of 8,162 feet, Hot Springs County receives approximately 21.9 inches of rainfall annually with predominantly loam soil. Summer highs average 83ยฐF, so choose short-season varieties of Scallions to ensure they mature before fall.

Hot Springs County, WY (Zone 4b) Short season
144 days
Last Spring Frost May 11
144 growing days
First Fall Frost October 2

Hot Springs County Soil Profile

Soil Type

Loam

Soil pH

6.3-7.8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (57 days to spare)
Start indoors: Mar 25 Transplant: May 6 🍅 Harvest: Jul 1 – Jul 29
Recommended (50%) ✓ Fits season (60 days to spare)
Start indoors: Mar 30 Transplant: May 11 🍅 Harvest: Jul 6 – Aug 3
Safe Start (90%) ✓ Fits season (62 days to spare)
Start indoors: Apr 10 Transplant: May 22 🍅 Harvest: Jul 17 – Aug 14

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 Hot Springs County

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

Soil pH

Your soil pH (6.3โ€“7.8) is more alkaline than Scallions prefers (6.0โ€“7.0). Add sulfur or peat moss to lower pH.

Soil Texture

The loam soil in Hot Springs County is excellent for Scallions โ€” good drainage, moisture retention, and nutrient holding capacity.

Drainage

Drainage is adequate for Scallions.

Organic Matter

Organic matter is moderate (2.3%). Annual compost additions will help Scallions.

How to Plant Scallions

0.5"
Planting Depth
6"
Between Plants
12"
Between Rows

Fall planting: Sow 12 weeks before your first frost date for a fall harvest.

Succession Planting Scallions

3
successive plantings in your 144-day season

Sow every 5.7 weeks. Last sowing by Jul 24 to harvest before frost.

For a dedicated fall crop, sow by Jul 10.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.6″/week
You supply
0.8″/week
Watering frequency 2-3 times/week
Season total 1,017 gal / 100 sq ft
Drought risk

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

Monthly Watering Guide for Scallions

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

Month Scallions Needs Rainfall You Supplement Action
Jan โ€” 1.4" 0" โ„๏ธ Dormant
Feb โ€” 1.2" 0" โ„๏ธ Dormant
Mar โ€” 2" 0" โ„๏ธ Dormant
Apr โ€” 2" 0" โ„๏ธ Dormant
May 4.3" 2.5" 1.8" ๐Ÿ’ง Light watering
Jun 4.3" 1.4" 2.9" ๐Ÿšฟ Regular watering
Jul 4.3" 2.2" 2.1" ๐Ÿ’ง Light watering
Aug 4.3" 2.4" 1.9" ๐Ÿ’ง Light watering
Sep 4.3" 1.8" 2.5" ๐Ÿšฟ Regular watering
Oct 4.3" 2.1" 2.2" ๐Ÿšฟ Regular watering
Nov โ€” 1.7" 0" โ„๏ธ Dormant
Dec โ€” 1.2" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Mayโ€“Oct in Hot Springs County). Supplement amounts are based on average rainfall โ€” actual needs vary with temperature, soil, and mulching.

Scallions 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" โ€” every day above 50ยฐF 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.

Scallions needs ~735 GDD — county provides 1,764 GDD Excellent fit

Scallions Planting Timeline โ€” Hot Springs County, WY

Scallions Planting Calendar

Activity When Date Range
Start Indoors March 30 Mar 30 โ€“ Apr 13
Transplant Outdoors May 11 May 11 โ€“ May 25
Direct Sow May 4 May 4 โ€“ May 25
Harvest July 6 Jul 6 โ€“ Aug 3
Fall Sowing July 10 Jul 10 โ€“ Jul 24

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

Month-by-Month Timeline

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

Growing Conditions

โ˜€๏ธ Sun

Full Sun (6-8+ hours)

๐Ÿ’ง Water

1"/week ยท 2-3 times/week

๐Ÿ“… Days to Maturity

50โ€“70 days

๐Ÿงช Soil pH

Needs 6โ€“7 ยท Your soil: too_alkaline

๐Ÿ—บ๏ธ USDA Zone

Zone 4b

๐Ÿ“† Growing Season

144 days in Hot Springs County

Growing Tips for Scallions in Hot Springs County

Direct sow Scallions outdoors after May 11 in Hot Springs County when soil has warmed and frost danger has passed.

Common pests for Scallions in this region include onion maggots and thrips. Use row covers early in the season and inspect plants weekly.

Hot Springs County receives only 22" of rain annually. Scallions needs consistent moisture โ€” install drip irrigation or water deeply 2-3 times per week.

General growing tips

Direct sow every 3 weeks for continuous harvest. Thin to 1 inch apart or grow in clusters. Harvest when pencil-thick by pulling or cutting at soil level.

Companion Planting

Good Companions

Avoid Planting Near

  • Peas
  • Green Beans

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Scallions in Hot Springs County, WY?

Hot Springs County is in Zone 4b with an average last frost of May 11. Plan your Scallions planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Hot Springs County, WY?

Hot Springs County, Wyoming is in USDA Hardiness Zone 4b. The average last spring frost is May 11 and first fall frost is October 2.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Hot Springs 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 Hot Springs County, WY. Local conditions may vary. Last updated: April 2026.