When to Plant Spinach in McPherson County, SD
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.
McPherson County, South Dakota is in USDA Zone 3b. The average last spring frost is May 11 and the first fall frost is September 27, giving you a growing season of approximately 139 days.
At an elevation of 637 feet, McPherson County receives approximately 21.4 inches of rainfall annually with predominantly loam soil. Summer highs average 79°F, so choose short-season varieties of Spinach to ensure they mature before fall.
McPherson 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 McPherson County
How your county's soil matches Spinach's growing requirements.
Soil pH
Your soil pH (6.7–7.9) overlaps with Spinach's range (6.5–7.5), though not a perfect match.
Soil Texture
The loam soil in McPherson County is excellent for Spinach — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is excellent (4.0%) — Spinach will thrive.
How to Plant Spinach
Fall planting: Sow 12 weeks before your first frost date for a fall harvest.
Succession Planting Spinach
Sow every 4 weeks. Last sowing by Aug 08 to harvest before frost.
For a dedicated fall crop, sow by Jul 05.
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 | — | 0.6" | 0" | ❄️ Dormant |
| Feb | — | 0.8" | 0" | ❄️ Dormant |
| Mar | — | 1.5" | 0" | ❄️ Dormant |
| Apr | — | 2.2" | 0" | ❄️ Dormant |
| May | 3" | 2.8" | 0.2" | 💧 Light watering |
| Jun | 3" | 3.3" | 0" | ✅ Rainfall sufficient |
| Jul | 3" | 2.8" | 0.2" | 💧 Light watering |
| Aug | 3" | 2.7" | 0.3" | 💧 Light watering |
| Sep | 3" | 1.9" | 1.1" | 💧 Light watering |
| Oct | — | 1.5" | 0" | ❄️ Dormant |
| Nov | — | 0.8" | 0" | ❄️ Dormant |
| Dec | — | 0.5" | 0" | ❄️ Dormant |
Water needs are for active growing months only (May–Sep in McPherson 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 — McPherson County, SD
Spinach Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | March 30 | Mar 30 – Apr 13 |
| Transplant Outdoors | May 11 | May 11 – May 25 |
| Direct Sow | May 4 | May 4 – May 25 |
| Harvest | June 15 | Jun 15 – Aug 17 |
| Fall Sowing | July 5 | Jul 5 – Jul 19 |
Plant 0.5" deep · 6" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | Start Indoors |
| April | Start Indoors |
| May | Transplant Outdoors Direct Sow |
| June | Harvest |
| July | Fall Sowing Harvest |
| August | 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 3b
📆 Growing Season
139 days in McPherson County
Growing Tips for Spinach in McPherson County
Direct sow Spinach outdoors after May 11 in McPherson County when soil has warmed and frost danger has passed.
Your generous 139.0-day season in McPherson 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 McPherson County, SD?
McPherson County is in Zone 3b with an average last frost of May 11. Plan your Spinach planting based on this frost date — see the calendar above for exact timing.
What planting zone is McPherson County, SD?
McPherson County, South Dakota is in USDA Hardiness Zone 3b. The average last spring frost is May 11 and first fall frost is September 27.
Plan Your Garden with Confidence
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