When to Plant Spinach in Platte County, WY
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.
Platte County, Wyoming is in USDA Zone 5a. The average last spring frost is May 13 and the first fall frost is September 26, giving you a growing season of approximately 136 days.
At an elevation of 7,409 feet, Platte County receives approximately 18.5 inches of rainfall annually with predominantly loam soil. Summer highs average 83°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.
Platte County Soil Profile
Soil Type
Loam
Soil pH
6.5-8.3
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 Platte County
How your county's soil matches Spinach's growing requirements.
Soil pH
Your soil pH (6.5–8.3) overlaps with Spinach's range (6.5–7.5), though not a perfect match.
Soil Texture
The loam soil in Platte County is excellent for Spinach — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is moderate (2.9%). 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 Aug 07 to harvest before frost.
For a dedicated fall crop, sow by Jul 18.
Plant 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 | — | 1.3" | 0" | ❄️ Dormant |
| Feb | — | 1" | 0" | ❄️ Dormant |
| Mar | — | 1.7" | 0" | ❄️ Dormant |
| Apr | — | 2.2" | 0" | ❄️ Dormant |
| May | 3" | 2" | 1" | 💧 Light watering |
| Jun | 3" | 1.5" | 1.5" | 🚿 Regular watering |
| Jul | 3" | 1.5" | 1.5" | 🚿 Regular watering |
| Aug | 3" | 2" | 1" | 💧 Light watering |
| Sep | 3" | 1.3" | 1.7" | 🚿 Regular watering |
| Oct | — | 1.5" | 0" | ❄️ Dormant |
| Nov | — | 1.3" | 0" | ❄️ Dormant |
| Dec | — | 1.1" | 0" | ❄️ Dormant |
Water needs are for active growing months only (May–Sep in Platte 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 — Platte County, WY
Spinach Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | April 8 | Apr 8 – Apr 22 |
| Transplant Outdoors | May 13 | May 13 – May 27 |
| Direct Sow | April 29 | Apr 29 – May 20 |
| Harvest | June 17 | Jun 17 – Aug 19 |
| Fall Sowing | July 18 | Jul 18 – Aug 1 |
Plant 0.5" deep · 6" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | — |
| April | Start Indoors Direct Sow |
| May | Transplant Outdoors Direct Sow |
| June | Harvest |
| July | Fall Sowing Harvest |
| August | Fall Sowing Harvest |
| September | — |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Partial Shade (3-6 hours)
💧 Water
0.7"/week · Only during dry spells
📅 Days to Maturity
35–50 days
🧪 Soil pH
Needs 6.5–7.5 · Your soil: acceptable
🗺️ USDA Zone
Zone 5a
📆 Growing Season
136 days in Platte County
Growing Tips for Spinach in Platte County
Direct sow Spinach outdoors after May 13 in Platte County when soil has warmed and frost danger has passed.
Your generous 136.0-day season in Platte County allows multiple plantings of Spinach. Sow every 17.0 days for continuous harvest.
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 Platte County, WY?
Platte County is in Zone 5a with an average last frost of May 13. Plan your Spinach planting based on this frost date — see the calendar above for exact timing.
What planting zone is Platte County, WY?
Platte County, Wyoming is in USDA Hardiness Zone 5a. The average last spring frost is May 13 and first fall frost is September 26.
Plan Your Garden with Confidence
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