When to Plant Scallions in Niobrara County, WY
Top priorities for Niobrara County, Wyoming gardeners in May
Welcome to May in Zone 5a. These are the moves that will have the biggest impact on your growing season.
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Move scallions into the garden
Pinch off the lowest leaves on each seedling before you plant — it reduces water loss while the roots catch up.
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Seed scallions outdoors
Succession planting is the secret here. Put in a row now, another in 2 weeks, a third in 4.
Before June arrives, get these ready
- Starting indoors: scallions
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.
Niobrara County, Wyoming is in USDA Zone 5a. The average last spring frost is May 15 and the first fall frost is September 21, giving you a growing season of approximately 129 days.
At an elevation of 5,262 feet, Niobrara County receives approximately 19.5 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.
Niobrara County Soil Profile
Soil Type
Loam
Soil pH
6.2-7.9
Drainage
Well Drained
Plant Planting Risk Windows
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 Niobrara County
How your county's soil matches Scallions's growing requirements.
Soil pH
Your soil pH (6.2–7.9) is more alkaline than Scallions prefers (6.0–7.0). Add sulfur or peat moss to lower pH.
Soil Texture
The loam soil in Niobrara County is excellent for Scallions — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is moderate (2.2%). Annual compost additions will help Scallions.
How to Plant Scallions
Fall planting: Sow 10 weeks before your first frost date for a fall harvest.
Succession Planting Scallions
Sow every 5.7 weeks. Last sowing by Jul 13 to harvest before frost.
For a dedicated fall crop, sow by Jul 13.
Plant Water Budget
Water stress score is 6/10 — 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 | — | 1.2" | 0" | ❄️ Dormant |
| Feb | — | 1.2" | 0" | ❄️ Dormant |
| Mar | — | 1.8" | 0" | ❄️ Dormant |
| Apr | — | 2.1" | 0" | ❄️ Dormant |
| May | 4.3" | 2.2" | 2.1" | 💧 Light watering |
| Jun | 4.3" | 1.3" | 3" | 🚿 Regular watering |
| Jul | 4.3" | 1.8" | 2.5" | 🚿 Regular watering |
| Aug | 4.3" | 2.1" | 2.2" | 🚿 Regular watering |
| Sep | 4.3" | 1.5" | 2.8" | 🚿 Regular watering |
| Oct | — | 1.7" | 0" | ❄️ Dormant |
| Nov | — | 1.5" | 0" | ❄️ Dormant |
| Dec | — | 1.1" | 0" | ❄️ Dormant |
Water needs are for active growing months only (May–Sep in Niobrara 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 Planting Timeline — Niobrara County, WY
Scallions Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | April 10 | Apr 10 – Apr 24 |
| Transplant Outdoors | May 15 | May 15 – May 29 |
| Direct Sow | May 1 | May 1 – May 22 |
| Harvest | July 10 | Jul 10 – Aug 7 |
| Fall Sowing | July 13 | Jul 13 – Jul 27 |
Plant 0.5" deep · 6" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | — |
| April | Start Indoors |
| May | Transplant Outdoors Direct Sow |
| June | — |
| 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 5a
📆 Growing Season
129 days in Niobrara County
Growing Tips for Scallions in Niobrara County
Direct sow Scallions outdoors after May 15 in Niobrara 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.
Niobrara County receives only 20" 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
Check more plant combinations with our Companion Planting Checker →
Scallions in Other Locations
Frequently Asked Questions
When should I plant Scallions in Niobrara County, WY?
Niobrara County is in Zone 5a with an average last frost of May 15. Plan your Scallions planting based on this frost date — see the calendar above for exact timing.
What planting zone is Niobrara County, WY?
Niobrara County, Wyoming is in USDA Hardiness Zone 5a. The average last spring frost is May 15 and first fall frost is September 21.
Your Niobrara County Garden Planner — Free
A 24-page printable planner built for Niobrara County (Zone 5a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.