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When to Plant Scallions in Wheatland County, MT

Wheatland County, Montana Zone 4a April

Wheatland County, Montana gardeners: here's your April plan

Here's what deserves your attention in Wheatland County, Montana this month. Everything below is tailored to Zone 4a and timed around your local frost dates.

Avg. last frost May 19
Avg. first frost September 21
Soil temp (4") 18°F
Watering High
Pest pressure Low
Daylight 13.3 hrs
A few tasks this April that'll pay off in May
  • Transplants going out: scallions
  • Direct-sowing: scallions

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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.

Wheatland County, Montana is in USDA Zone 4a. The average last spring frost is May 19 and the first fall frost is September 21, giving you a growing season of approximately 125 days.

At an elevation of 7,916 feet, Wheatland County receives approximately 19.2 inches of rainfall annually with predominantly loam soil. Summer highs average 82°F, so choose short-season varieties of Scallions to ensure they mature before fall. With low rainfall, drip irrigation is essential for growing Scallions successfully. Mulch heavily to conserve soil moisture.

Wheatland County, MT (Zone 4a) Short season
125 days
Last Spring Frost May 19
125 growing days
First Fall Frost September 21

Wheatland 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 (43 days to spare)
Start indoors: Mar 31 Transplant: May 12 🍅 Harvest: Jul 7 – Aug 4
Recommended (50%) ✓ Fits season (41 days to spare)
Start indoors: Apr 7 Transplant: May 19 🍅 Harvest: Jul 14 – Aug 11
Safe Start (90%) ✓ Fits season (49 days to spare)
Start indoors: Apr 18 Transplant: May 30 🍅 Harvest: Jul 25 – Aug 22

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 Wheatland County

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

Soil pH

Your soil pH (6.6–7.8) is more alkaline than Scallions prefers (6.0–7.0). Add sulfur or peat moss to lower pH.

Soil Texture

The loam soil in Wheatland County is excellent for Scallions — good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is moderate (2.4%). 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

2
successive plantings in your 125-day season

Sow every 5.7 weeks. Last sowing by Jul 13 to harvest before frost.

For a dedicated fall crop, sow by Jun 29.

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 474 gal / 100 sq ft
Drought risk

Water stress score is 8/10 — 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 1.4" 0" ❄️ Dormant
Feb 1" 0" ❄️ Dormant
Mar 1.6" 0" ❄️ Dormant
Apr 2.3" 0" ❄️ Dormant
May 4.3" 2" 2.3" 🚿 Regular watering
Jun 4.3" 1.2" 3.1" 🚿 Regular watering
Jul 4.3" 1.9" 2.4" 🚿 Regular watering
Aug 4.3" 1.8" 2.5" 🚿 Regular watering
Sep 4.3" 1.6" 2.7" 🚿 Regular watering
Oct 1.9" 0" ❄️ Dormant
Nov 1.5" 0" ❄️ Dormant
Dec 1.1" 0" ❄️ Dormant

Water needs are for active growing months only (May–Sep in Wheatland County). Supplement amounts are based on average rainfall — 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" — every day above 50°F 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 ~690 GDD — county provides 1,437 GDD Excellent fit

Scallions Planting Timeline — Wheatland County, MT

Scallions Planting Calendar

Activity When Date Range
Start Indoors April 7 Apr 7 – Apr 21
Transplant Outdoors May 19 May 19 – Jun 2
Direct Sow May 12 May 12 – Jun 2
Harvest July 14 Jul 14 – Aug 11
Fall Sowing June 29 Jun 29 – Jul 13

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 Direct Sow Fall Sowing
July Fall Sowing Harvest
August Harvest
September
October
November
December

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · 1-2 times/week

📅 Days to Maturity

50–70 days

🧪 Soil pH

Needs 6–7 · Your soil: too_alkaline

🗺️ USDA Zone

Zone 4a

📆 Growing Season

125 days in Wheatland County

Growing Tips for Scallions in Wheatland County

Direct sow Scallions outdoors after May 19 in Wheatland 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.

Wheatland County receives only 19" of rain annually. Scallions needs consistent moisture — 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 Wheatland County, MT?

Wheatland County is in Zone 4a with an average last frost of May 19. Plan your Scallions planting based on this frost date — see the calendar above for exact timing.

What planting zone is Wheatland County, MT?

Wheatland County, Montana is in USDA Hardiness Zone 4a. The average last spring frost is May 19 and first fall frost is September 21.

🌱

Your Wheatland County Garden Planner — Free

A 24-page printable planner built for Wheatland County (Zone 4a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

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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 Wheatland County, MT. Local conditions may vary. Last updated: April 2026.

Sources & credits

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