When to Plant Spinach in Douglas County, OR
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.
Douglas County, Oregon is in USDA Zone 8a. The average last spring frost is April 4 and the first fall frost is November 5, giving you a growing season of approximately 215 days.
At an elevation of 377 feet, Douglas County receives approximately 52.6 inches of rainfall annually with predominantly silt loam soil. Summer highs average 90°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.
Douglas County Soil Profile
Soil Type
Silt Loam
Soil pH
5.8-6.4
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 Douglas County
How your county's soil matches Spinach's growing requirements.
Soil pH
Your soil pH (5.8–6.4) is more acidic than Spinach prefers (6.5–7.5). Add garden lime to raise pH.
Soil Texture
The silt loam soil in Douglas County is excellent for Spinach — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is excellent (5.4%) — 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 16 to harvest before frost.
For a dedicated fall crop, sow by Aug 27.
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 | — | 8.6" | 0" | ❄️ Dormant |
| Feb | — | 6.2" | 0" | ❄️ Dormant |
| Mar | — | 4.9" | 0" | ❄️ Dormant |
| Apr | 3" | 4.3" | 0" | ✅ Rainfall sufficient |
| May | 3" | 3.4" | 0" | ✅ Rainfall sufficient |
| Jun | 3" | 2.3" | 0.7" | 💧 Light watering |
| Jul | 3" | 0.8" | 2.2" | 🚿 Regular watering |
| Aug | 3" | 1" | 2" | 🚿 Regular watering |
| Sep | 3" | 2.2" | 0.8" | 💧 Light watering |
| Oct | 3" | 4" | 0" | ✅ Rainfall sufficient |
| Nov | 3" | 7.6" | 0" | ✅ Rainfall sufficient |
| Dec | — | 7.4" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Nov in Douglas 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 — Douglas County, OR
Spinach Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | February 28 | Feb 28 – Mar 14 |
| Transplant Outdoors | April 4 | Apr 4 – Apr 18 |
| Direct Sow | March 21 | Mar 21 – Apr 11 |
| Harvest | May 9 | May 9 – Jul 11 |
| Fall Sowing | August 27 | Aug 27 – Sep 10 |
Plant 0.5" deep · 6" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | Start Indoors |
| March | Start Indoors Direct Sow |
| April | Transplant Outdoors Direct Sow |
| May | Harvest |
| June | Harvest |
| July | Harvest |
| 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 8a
📆 Growing Season
215 days in Douglas County
Growing Tips for Spinach in Douglas County
Direct sow Spinach outdoors after April 04 in Douglas County when soil has warmed and frost danger has passed.
Your generous 215.0-day season in Douglas 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 Douglas 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 Douglas County, OR?
Douglas County is in Zone 8a with an average last frost of April 4. Plan your Spinach planting based on this frost date — see the calendar above for exact timing.
What planting zone is Douglas County, OR?
Douglas County, Oregon is in USDA Hardiness Zone 8a. The average last spring frost is April 4 and first fall frost is November 5.
Plan Your Garden with Confidence
Get our free Garden Planner — designed to help Douglas County gardeners in Zone 8a organize planting dates, track what's growing, and never miss a planting window.
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