When to Plant Spinach in Bingham County, ID
What to do in May
May is a pivotal month for Bingham County, Idaho gardens. Focus on these tasks first and you'll set up the rest of the season for success.
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Transplant spinach outside
Harden off for 7 days — a little more sun each day — before planting. That's the difference between a seedling that thrives and one that stalls.
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Sow spinach where they'll grow
These tolerate cool soil, so you're not gambling by sowing now.
To set up a strong June, finish these tasks
- 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.
Bingham County, Idaho is in USDA Zone 5b. The average last spring frost is May 21 and the first fall frost is September 21, giving you a growing season of approximately 123 days.
At an elevation of 8,345 feet, Bingham County receives approximately 24.5 inches of rainfall annually with predominantly loam soil. Summer highs average 86°F, providing good warmth for Spinach during the growing season.
Bingham County Soil Profile
Soil Type
Loam
Soil pH
6.3-7.7
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 Bingham County
How your county's soil matches Spinach's growing requirements.
Soil pH
Your soil pH (6.3–7.7) overlaps with Spinach's range (6.5–7.5), though not a perfect match.
Soil Texture
The loam soil in Bingham County is excellent for Spinach — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is moderate (2.6%). 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 02 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 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 | — | 1.5" | 0" | ❄️ Dormant |
| Feb | — | 1.4" | 0" | ❄️ Dormant |
| Mar | — | 2.1" | 0" | ❄️ Dormant |
| Apr | — | 2.9" | 0" | ❄️ Dormant |
| May | 3" | 2.5" | 0.5" | 💧 Light watering |
| Jun | 3" | 1.5" | 1.5" | 🚿 Regular watering |
| Jul | 3" | 2.3" | 0.7" | 💧 Light watering |
| Aug | 3" | 2.5" | 0.5" | 💧 Light watering |
| Sep | 3" | 2.3" | 0.7" | 💧 Light watering |
| Oct | — | 2.4" | 0" | ❄️ Dormant |
| Nov | — | 1.8" | 0" | ❄️ Dormant |
| Dec | — | 1.2" | 0" | ❄️ Dormant |
Water needs are for active growing months only (May–Sep in Bingham 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 — Bingham County, ID
Spinach Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | April 16 | Apr 16 – Apr 30 |
| Transplant Outdoors | May 21 | May 21 – Jun 4 |
| Direct Sow | May 7 | May 7 – May 28 |
| Harvest | June 25 | Jun 25 – Aug 27 |
| 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 | Transplant Outdoors Harvest |
| July | Fall Sowing Harvest |
| August | Harvest |
| September | — |
| 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 5b
📆 Growing Season
123 days in Bingham County
Growing Tips for Spinach in Bingham County
Direct sow Spinach outdoors after May 21 in Bingham 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.
Recommended Spinach Varieties for Bingham County
Slow-bolting spinach for warm springs — best as fall crop here
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 Bingham County, ID?
Bingham County is in Zone 5b with an average last frost of May 21. Plan your Spinach planting based on this frost date — see the calendar above for exact timing.
What planting zone is Bingham County, ID?
Bingham County, Idaho is in USDA Hardiness Zone 5b. The average last spring frost is May 21 and first fall frost is September 21.
Your Bingham County Garden Planner — Free
A 24-page printable planner built for Bingham 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.