When to Plant Spinach in Clark County, OH
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.
Clark County, Ohio is in USDA Zone 6a. The average last spring frost is April 18 and the first fall frost is October 21, giving you a growing season of approximately 186 days.
At an elevation of 721 feet, Clark County receives approximately 34.8 inches of rainfall annually with predominantly silt loam soil. Summer highs average 88°F, providing good warmth for Spinach during the growing season.
Clark County Soil Profile
Soil Type
Silt Loam
Soil pH
6-7.1
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 Clark County
How your county's soil matches Spinach's growing requirements.
Soil pH
Your soil pH (6.0–7.1) overlaps with Spinach's range (6.5–7.5), though not a perfect match.
Soil Texture
The silt loam soil in Clark County is excellent for Spinach — good drainage, moisture retention, and nutrient holding capacity.
Drainage
Drainage is adequate for Spinach.
Organic Matter
Organic matter is excellent (4.3%) — 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 Sep 01 to harvest before frost.
For a dedicated fall crop, sow by Aug 12.
Plant Water Budget
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 | — | 1.7" | 0" | ❄️ Dormant |
| Mar | — | 2.9" | 0" | ❄️ Dormant |
| Apr | 3" | 3.1" | 0" | ✅ Rainfall sufficient |
| May | 3" | 3.7" | 0" | ✅ Rainfall sufficient |
| Jun | 3" | 4" | 0" | ✅ Rainfall sufficient |
| Jul | 3" | 4.3" | 0" | ✅ Rainfall sufficient |
| Aug | 3" | 3.3" | 0" | ✅ Rainfall sufficient |
| Sep | 3" | 3.1" | 0" | ✅ Rainfall sufficient |
| Oct | 3" | 2.8" | 0.2" | 💧 Light watering |
| Nov | — | 2.2" | 0" | ❄️ Dormant |
| Dec | — | 2.3" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Oct in Clark 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 — Clark County, OH
Spinach Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | March 14 | Mar 14 – Mar 28 |
| Transplant Outdoors | April 18 | Apr 18 – May 2 |
| Direct Sow | April 4 | Apr 4 – Apr 25 |
| Harvest | May 23 | May 23 – Jul 25 |
| Fall Sowing | August 12 | Aug 12 – Aug 26 |
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 | Transplant Outdoors Harvest |
| June | Harvest |
| July | Harvest |
| August | Fall Sowing |
| 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 6a
📆 Growing Season
186 days in Clark County
Growing Tips for Spinach in Clark County
Direct sow Spinach outdoors after April 18 in Clark County when soil has warmed and frost danger has passed.
Your generous 186.0-day season in Clark 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 Clark 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 Clark County, OH?
Clark County is in Zone 6a with an average last frost of April 18. Plan your Spinach planting based on this frost date — see the calendar above for exact timing.
What planting zone is Clark County, OH?
Clark County, Ohio is in USDA Hardiness Zone 6a. The average last spring frost is April 18 and first fall frost is October 21.
Plan Your Garden with Confidence
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