When to Plant Scallions in Montrose County, CO
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.
Montrose County, Colorado is in USDA Zone 6a. The average last spring frost is June 13 and the first fall frost is September 12, giving you a growing season of approximately 91 days.
At an elevation of 6,494 feet, Montrose County receives approximately 18.4 inches of rainfall annually with predominantly loam soil. Summer highs average 87°F, providing good warmth for Scallions during the growing season. With low rainfall, drip irrigation is essential for growing Scallions successfully. Mulch heavily to conserve soil moisture.
Montrose County Soil Profile
Soil Type
Loam
Soil pH
6.7-7.9
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 Montrose County
How your county's soil matches Scallions's growing requirements.
Soil pH
Your soil pH (6.7–7.9) is more alkaline than Scallions prefers (6.0–7.0). Add sulfur or peat moss to lower pH.
Soil Texture
The loam soil in Montrose County is excellent for Scallions — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is moderate (2.5%). 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 04 to harvest before frost.
For a dedicated fall crop, sow by Jul 04.
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 | — | 1.4" | 0" | ❄️ Dormant |
| Feb | — | 1" | 0" | ❄️ Dormant |
| Mar | — | 1.4" | 0" | ❄️ Dormant |
| Apr | — | 2.2" | 0" | ❄️ Dormant |
| May | — | 2.3" | 0" | ❄️ Dormant |
| Jun | 4.3" | 1.2" | 3.1" | 🚿 Regular watering |
| Jul | 4.3" | 1.8" | 2.5" | 🚿 Regular watering |
| Aug | 4.3" | 1.7" | 2.6" | 🚿 Regular watering |
| Sep | 4.3" | 1.5" | 2.8" | 🚿 Regular watering |
| Oct | — | 1.6" | 0" | ❄️ Dormant |
| Nov | — | 1.3" | 0" | ❄️ Dormant |
| Dec | — | 1.1" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Jun–Sep in Montrose 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 — Montrose County, CO
Scallions Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | May 9 | May 9 – May 23 |
| Transplant Outdoors | June 13 | Jun 13 – Jun 27 |
| Direct Sow | May 30 | May 30 – Jun 20 |
| Harvest | August 8 | Aug 8 – Sep 5 |
| Fall Sowing | July 4 | Jul 4 – Jul 18 |
Plant 0.5" deep · 6" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | — |
| April | — |
| May | Start Indoors Direct Sow |
| June | Transplant Outdoors Direct Sow |
| July | Fall Sowing |
| August | Harvest |
| September | Harvest |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
1"/week · Only during dry spells
📅 Days to Maturity
50–70 days
🧪 Soil pH
Needs 6–7 · Your soil: too_alkaline
🗺️ USDA Zone
Zone 6a
📆 Growing Season
91 days in Montrose County
Growing Tips for Scallions in Montrose County
Direct sow Scallions outdoors after June 13 in Montrose 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.
Montrose County receives only 18" 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
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Check more plant combinations with our Companion Planting Checker →
Scallions in Other Locations
Frequently Asked Questions
When should I plant Scallions in Montrose County, CO?
Montrose County is in Zone 6a with an average last frost of June 13. Plan your Scallions planting based on this frost date — see the calendar above for exact timing.
What planting zone is Montrose County, CO?
Montrose County, Colorado is in USDA Hardiness Zone 6a. The average last spring frost is June 13 and first fall frost is September 12.
Plan Your Garden with Confidence
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