When to plant Spinach in Silver Bow County, MT
The best window to plant Spinach in Silver Bow County, is June 1–June 22, when soil warms to 50°F. Last frost typically hits June 15; first frost September 7. A second sowing from June 29 to July 13 extends the harvest into fall.
When to Plant Spinach in Silver Bow County, MT
June in the garden — Silver Bow County, Montana
June rewards gardeners who work with the weather, not against it. Here's how to stay in step this month in Silver Bow County, Montana.
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Transplant spinach outside
Pinch off the lowest leaves on each seedling before you plant — it reduces water loss while the roots catch up.
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Plant spinach from seed, right in the garden
Your soil is 48°F — warm enough for these to germinate without babying.
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Plant your fall garden: spinach
Mid-season soil is hot. Sow a bit deeper than the packet suggests to find cooler, damper ground.
Get ahead of July
- Starting indoors: spinach
- First harvests: spinach
Spinach is a nutrient-packed cool-season green that grows quickly in spring and fall. It is rich in iron, vitamins, and antioxidants and excellent raw or cooked.
Silver Bow County, Montana is in USDA Zone 5a. The average last spring frost is June 15 and the first fall frost is September 7, giving you a growing season of approximately 84 days.
At an elevation of 5,305 feet, Silver Bow County receives approximately 14.3 inches of rainfall annually with predominantly loam soil. Summer highs average 84°F, so choose short-season varieties of Spinach to ensure they mature before fall. With low rainfall, drip irrigation is essential for growing Spinach successfully. Mulch heavily to conserve soil moisture.
Silver Bow County Soil Profile
Soil Type
Loam
Soil pH
6.6-8.3
Drainage
Well Drained
Spinach 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 Silver Bow County
How your county's soil matches Spinach's growing requirements.
Soil pH
Your soil pH (6.6–8.3) overlaps with Spinach's range (6.5–7.5), though not a perfect match.
Soil Texture
The loam soil in Silver Bow County is excellent for Spinach — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is moderate (2.5%). Annual compost additions will help Spinach.
How to Plant Spinach
Fall planting: Sow 10 weeks before your first frost date for a fall harvest.
Succession Planting Spinach
Sow every 4 weeks. Last sowing by Jul 19 to harvest before frost.
For a dedicated fall crop, sow by Jun 29.
Spinach Water Budget
Water stress score is 8/10 — consider drought-tolerant varieties and mulching
Monthly Watering Guide for Spinach
Spinach needs approximately 0.7 inches of water per week (3" per month). Here's how your county's rainfall compares month by month.
| Month | Spinach Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 1.1" | 0" | ❄️ Dormant |
| Feb | — | 1" | 0" | ❄️ Dormant |
| Mar | — | 1.3" | 0" | ❄️ Dormant |
| Apr | — | 1.4" | 0" | ❄️ Dormant |
| May | — | 1.5" | 0" | ❄️ Dormant |
| Jun | 3" | 0.9" | 2.1" | 🚿 Regular watering |
| Jul | 3" | 1.1" | 1.9" | 🚿 Regular watering |
| Aug | 3" | 1.8" | 1.2" | 💧 Light watering |
| Sep | 3" | 1.1" | 1.9" | 🚿 Regular watering |
| Oct | — | 1.1" | 0" | ❄️ Dormant |
| Nov | — | 1" | 0" | ❄️ Dormant |
| Dec | — | 0.9" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Jun–Sep in Silver Bow County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Spinach 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.
Spinach Planting Timeline — Silver Bow County, MT
Spinach Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | May 11 | May 11 – May 25 |
| Transplant Outdoors | June 15 | Jun 15 – Jun 29 |
| Direct Sow | June 1 | Jun 1 – Jun 22 |
| Harvest | July 20 | Jul 20 – Sep 21 |
| Fall Sowing | June 29 | Jun 29 – Jul 13 |
Plant 0.5" deep · 6" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | — |
| April | — |
| May | Start Indoors |
| June | Transplant Outdoors Direct Sow Fall Sowing |
| July | Fall Sowing Harvest |
| August | Harvest |
| September | Harvest |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Partial Shade (3-6 hours)
💧 Water
0.7"/week · Natural rainfall sufficient
📅 Days to Maturity
35–50 days
🧪 Soil pH
Needs 6.5–7.5 · Your soil: acceptable
🗺️ USDA Zone
Zone 5a
📆 Growing Season
84 days in Silver Bow County
Growing Tips for Spinach in Silver Bow County
Direct sow Spinach outdoors after June 15 in Silver Bow County when soil has warmed and frost danger has passed.
General growing tips
Direct sow as soon as soil can be worked in spring. Plant in partial shade for summer crops to delay bolting. Succession plant every 2 weeks for continuous harvest.
Companion Planting
Good Companions
Check more plant combinations with our Companion Planting Checker →
Wind pollinated — isolate 1/2 mile for purity. Easy to let bolt in heat.
Spinach in Other Locations
Frequently Asked Questions
When should I plant Spinach in Silver Bow County, MT?
Silver Bow County is in Zone 5a with an average last frost of June 15. Plan your Spinach planting based on this frost date — see the calendar above for exact timing.
What planting zone is Silver Bow County, MT?
Silver Bow County, Montana is in USDA Hardiness Zone 5a. The average last spring frost is June 15 and first fall frost is September 7.
When should I plant Spinach in Silver Bow County, MT?
In Silver Bow County, MT, plant Spinach after the last frost (around June 15) and before the first frost (around September 7). Best results when soil holds above 50°F.
What growing zone is Silver Bow County, MT for Spinach?
Silver Bow County sits in USDA Zone 5a. Spinach grows reliably in zones 2a through 10b, so it's a good fit here.
Can Spinach grow in Silver Bow County's climate?
Yes — Spinach grows well in Silver Bow County's temperate climate. Silver Bow County averages a 84-day frost-free season, with last frost around June 15 and first frost around September 7.
Your Silver Bow County Garden Planner — Free
A 22-page printable planner built for Silver Bow 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.