When to plant Spinach in Union County, AR
Plant Spinach in Union County from March 8 to March 29 in spring. Union County sits in USDA Zone 8b, with last frost around March 22 and first frost on November 3. A second sowing from August 25 to September 8 extends the harvest into fall.
When to Plant Spinach in Union County, AR
Your July planting checklist for Union County, Arkansas
We've pulled the most time-sensitive tasks for Union County, Arkansas this July and put them front and centre. Tackle them in order.
To set up a strong August, finish these tasks
- Fall sowing: 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.
Union County, Arkansas is in USDA Zone 8b. The average last spring frost is March 22 and the first fall frost is November 3, giving you a growing season of approximately 226 days.
At an elevation of 508 feet, Union County receives approximately 52 inches of rainfall annually with predominantly silt loam soil. Summer highs average 92°F, providing good warmth for Spinach during the growing season. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Spinach root diseases.
Union County Soil Profile
Soil Type
Silt Loam
Soil pH
5.8-6.6
Drainage
Well Drained
Spinach 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 Union County
How your county's soil matches Spinach's growing requirements.
Soil pH
Your soil pH (5.8–6.6) is more acidic than Spinach prefers (6.5–7.5). Add garden lime to raise pH.
Soil Texture
The silt loam soil in Union County is excellent for Spinach — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is moderate (2.7%). 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 Sep 14 to harvest before frost.
For a dedicated fall crop, sow by Aug 25.
Spinach 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 | — | 4.8" | 0" | ❄️ Dormant |
| Feb | — | 4.5" | 0" | ❄️ Dormant |
| Mar | 3" | 4.5" | 0" | ✅ Rainfall sufficient |
| Apr | 3" | 3.9" | 0" | ✅ Rainfall sufficient |
| May | 3" | 4.6" | 0" | ✅ Rainfall sufficient |
| Jun | 3" | 4.4" | 0" | ✅ Rainfall sufficient |
| Jul | 3" | 5.1" | 0" | ✅ Rainfall sufficient |
| Aug | 3" | 5.1" | 0" | ✅ Rainfall sufficient |
| Sep | 3" | 4.2" | 0" | ✅ Rainfall sufficient |
| Oct | 3" | 3.5" | 0" | ✅ Rainfall sufficient |
| Nov | 3" | 3.8" | 0" | ✅ Rainfall sufficient |
| Dec | — | 3.6" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Mar–Nov in Union 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 — Union County, AR
Spinach Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | February 15 | Feb 15 – Mar 1 |
| Transplant Outdoors | March 22 | Mar 22 – Apr 5 |
| Direct Sow | March 8 | Mar 8 – Mar 29 |
| Harvest | April 26 | Apr 26 – Jun 28 |
| Fall Sowing | August 25 | Aug 25 – Sep 8 |
Plant 0.5" deep · 6" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | Start Indoors |
| March | Start Indoors Transplant Outdoors Direct Sow |
| April | Transplant Outdoors Harvest |
| May | Harvest |
| June | Harvest |
| July | — |
| August | Fall Sowing |
| September | Fall Sowing |
| 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: too_acidic
🗺️ USDA Zone
Zone 8b
📆 Growing Season
226 days in Union County
Growing Tips for Spinach in Union County
Direct sow Spinach outdoors after March 22 in Union County when soil has warmed and frost danger has passed.
Summer highs in Union County reach 92°F — grow Spinach as a spring or fall crop. Use shade cloth if planting in summer.
Your generous 226.0-day season in Union 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 Union 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 Union County, AR?
Union County is in Zone 8b with an average last frost of March 22. Plan your Spinach planting based on this frost date — see the calendar above for exact timing.
What planting zone is Union County, AR?
Union County, Arkansas is in USDA Hardiness Zone 8b. The average last spring frost is March 22 and first fall frost is November 3.
When should I plant Spinach in Union County, AR?
In Union County, AR, plant Spinach after the last frost (around March 22) and before the first frost (around November 3). Best results when soil holds above 50°F.
What growing zone is Union County, AR for Spinach?
Union County sits in USDA Zone 8b. Spinach grows reliably in zones 2a through 10b, so it's a good fit here.
Can Spinach grow in Union County's climate?
Yes — Spinach grows well in Union County's temperate climate. Union County averages a 226-day frost-free season, with last frost around March 22 and first frost around November 3.
Your Union County Garden Planner — Free
A 22-page printable planner built for Union County (Zone 8b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.