When to Plant Scallions in Summit County, UT
July in Summit County, Utah — your action list
If you only do a handful of things in the garden this July, make it these. They're sequenced around your zone's frost timing.
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Begin indoor sowing: scallions
Bottom-water once the first true leaves appear — it keeps stems dry and knocks back damping-off.
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Sow scallions for an autumn harvest
Mid-season soil is hot. Sow a bit deeper than the packet suggests to find cooler, damper ground.
Before August arrives, get these ready
- First harvests: 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.
Summit County, Utah is in USDA Zone 5b. The average last spring frost is June 10 and the first fall frost is September 12, giving you a growing season of approximately 94 days.
At an elevation of 8,145 feet, Summit County receives approximately 24.8 inches of rainfall annually with predominantly loam soil. Summer highs average 86°F, providing good warmth for Scallions during the growing season.
Summit County Soil Profile
Soil Type
Loam
Soil pH
6.4-8.3
Drainage
Well Drained
Scallions 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 Summit County
How your county's soil matches Scallions's growing requirements.
Soil pH
Your soil pH (6.4–8.3) is more alkaline than Scallions prefers (6.0–7.0). Add sulfur or peat moss to lower pH.
Soil Texture
The loam soil in Summit County is excellent for Scallions — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is moderate (2.3%). 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.
Scallions Water Budget
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 | — | 1.6" | 0" | ❄️ Dormant |
| Feb | — | 1.3" | 0" | ❄️ Dormant |
| Mar | — | 2.4" | 0" | ❄️ Dormant |
| Apr | — | 2.9" | 0" | ❄️ Dormant |
| May | — | 2.9" | 0" | ❄️ Dormant |
| Jun | 4.3" | 1.8" | 2.5" | 🚿 Regular watering |
| Jul | 4.3" | 1.9" | 2.4" | 🚿 Regular watering |
| Aug | 4.3" | 2.5" | 1.8" | 💧 Light watering |
| Sep | 4.3" | 2" | 2.3" | 🚿 Regular watering |
| Oct | — | 2.1" | 0" | ❄️ Dormant |
| Nov | — | 2" | 0" | ❄️ Dormant |
| Dec | — | 1.4" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Jun–Sep in Summit 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 — Summit County, UT
Scallions Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | May 6 | May 6 – May 20 |
| Transplant Outdoors | June 10 | Jun 10 – Jun 24 |
| Direct Sow | May 27 | May 27 – Jun 17 |
| Harvest | August 5 | Aug 5 – Sep 2 |
| 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 · Natural rainfall sufficient
📅 Days to Maturity
50–70 days
🧪 Soil pH
Needs 6–7 · Your soil: too_alkaline
🗺️ USDA Zone
Zone 5b
📆 Growing Season
94 days in Summit County
Growing Tips for Scallions in Summit County
Direct sow Scallions outdoors after June 10 in Summit 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.
Summit County receives only 25" 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 Summit County, UT?
Summit County is in Zone 5b with an average last frost of June 10. Plan your Scallions planting based on this frost date — see the calendar above for exact timing.
What planting zone is Summit County, UT?
Summit County, Utah is in USDA Hardiness Zone 5b. The average last spring frost is June 10 and first fall frost is September 12.
Your Summit County Garden Planner — Free
A 22-page printable planner built for Summit County (Zone 5b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.