When to Plant Spinach in Sangamon County, IL
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.
Sangamon County, Illinois is in USDA Zone 5b. The average last spring frost is April 15 and the first fall frost is October 17, giving you a growing season of approximately 185 days.
At an elevation of 1,204 feet, Sangamon County receives approximately 41.1 inches of rainfall annually with predominantly silt loam soil. Summer highs average 85°F, providing good warmth for Spinach during the growing season.
Sangamon County Soil Profile
Soil Type
Silt Loam
Soil pH
6.2-7.2
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 Sangamon County
How your county's soil matches Spinach's growing requirements.
Soil pH
Your soil pH (6.2–7.2) overlaps with Spinach's range (6.5–7.5), though not a perfect match.
Soil Texture
The silt loam soil in Sangamon 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 10 weeks before your first frost date for a fall harvest.
Succession Planting Spinach
Sow every 4 weeks. Last sowing by Aug 28 to harvest before frost.
For a dedicated fall crop, sow by Aug 08.
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 | — | 1.9" | 0" | ❄️ Dormant |
| Feb | — | 1.9" | 0" | ❄️ Dormant |
| Mar | — | 2.5" | 0" | ❄️ Dormant |
| Apr | 3" | 4.5" | 0" | ✅ Rainfall sufficient |
| May | 3" | 4.5" | 0" | ✅ Rainfall sufficient |
| Jun | 3" | 5.8" | 0" | ✅ Rainfall sufficient |
| Jul | 3" | 4.1" | 0" | ✅ Rainfall sufficient |
| Aug | 3" | 4.3" | 0" | ✅ Rainfall sufficient |
| Sep | 3" | 3.3" | 0" | ✅ Rainfall sufficient |
| Oct | 3" | 3.3" | 0" | ✅ Rainfall sufficient |
| Nov | — | 2.6" | 0" | ❄️ Dormant |
| Dec | — | 2.3" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Oct in Sangamon 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 — Sangamon County, IL
Spinach Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | March 11 | Mar 11 – Mar 25 |
| Transplant Outdoors | April 15 | Apr 15 – Apr 29 |
| Direct Sow | April 1 | Apr 1 – Apr 22 |
| Harvest | May 20 | May 20 – Jul 22 |
| Fall Sowing | August 8 | Aug 8 – Aug 22 |
Plant 0.5" deep · 6" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | Start Indoors |
| April | Transplant Outdoors Direct Sow |
| May | Harvest |
| June | Harvest |
| July | Harvest |
| August | Fall Sowing |
| 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
185 days in Sangamon County
Growing Tips for Spinach in Sangamon County
Direct sow Spinach outdoors after April 15 in Sangamon County when soil has warmed and frost danger has passed.
Your generous 185.0-day season in Sangamon 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.
Recommended Spinach Varieties for Sangamon 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 Sangamon County, IL?
Sangamon County is in Zone 5b with an average last frost of April 15. Plan your Spinach planting based on this frost date — see the calendar above for exact timing.
What planting zone is Sangamon County, IL?
Sangamon County, Illinois is in USDA Hardiness Zone 5b. The average last spring frost is April 15 and first fall frost is October 17.
Plan Your Garden with Confidence
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