When to Plant Spinach in Amador County, CA
Top priorities for Amador County, California gardeners in May
Welcome to May in Zone 9b. These are the moves that will have the biggest impact on your growing season.
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Start harvesting spinach
Check every 1–2 days. Many of these get tough or go to seed if you wait too long.
To set up a strong June, finish these tasks
- First harvests: 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.
Amador County, California is in USDA Zone 9b. The average last spring frost is March 8 and the first fall frost is November 25, giving you a growing season of approximately 262 days.
At an elevation of 1,335 feet, Amador County receives approximately 42.7 inches of rainfall annually with predominantly loam soil. Summer highs average 89°F, providing good warmth for Spinach during the growing season.
Amador County Soil Profile
Soil Type
Loam
Soil pH
6.7-7.8
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 Amador County
How your county's soil matches Spinach's growing requirements.
Soil pH
Your soil pH (6.7–7.8) overlaps with Spinach's range (6.5–7.5), though not a perfect match.
Soil Texture
The loam soil in Amador 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 8 weeks before your first frost date for a fall harvest.
Succession Planting Spinach
Sow every 4 weeks. Last sowing by Oct 06 to harvest before frost.
For a dedicated fall crop, sow by Sep 30.
Plant Water Budget
Water stress score is 8/10 — 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 | — | 9.4" | 0" | ❄️ Dormant |
| Feb | — | 8" | 0" | ❄️ Dormant |
| Mar | 3" | 6" | 0" | ✅ Rainfall sufficient |
| Apr | 3" | 3.5" | 0" | ✅ Rainfall sufficient |
| May | 3" | 1" | 2" | 🚿 Regular watering |
| Jun | 3" | 0.2" | 2.8" | 🚿 Regular watering |
| Jul | 3" | 0" | 3" | 🚿 Regular watering |
| Aug | 3" | 0" | 3" | 🚿 Regular watering |
| Sep | 3" | 0.5" | 2.5" | 🚿 Regular watering |
| Oct | 3" | 1.9" | 1.1" | 💧 Light watering |
| Nov | 3" | 4.3" | 0" | ✅ Rainfall sufficient |
| Dec | — | 7.8" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Mar–Nov in Amador 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 — Amador County, CA
Spinach Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | February 8 | Feb 8 – Feb 22 |
| Transplant Outdoors | March 8 | Mar 8 – Mar 22 |
| Direct Sow | February 15 | Feb 15 – Mar 8 |
| Harvest | April 12 | Apr 12 – Jun 14 |
| Fall Sowing | September 30 | Sep 30 – Oct 14 |
Plant 0.5" deep · 6" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | Start Indoors Direct Sow |
| March | Transplant Outdoors Direct Sow |
| April | Harvest |
| May | Harvest |
| June | Harvest |
| July | — |
| August | — |
| September | Fall Sowing |
| October | Fall Sowing |
| 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 9b
📆 Growing Season
262 days in Amador County
Growing Tips for Spinach in Amador County
Direct sow Spinach outdoors after March 08 in Amador County when soil has warmed and frost danger has passed.
Your generous 262.0-day season in Amador 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 Amador 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 Amador County, CA?
Amador County is in Zone 9b with an average last frost of March 8. Plan your Spinach planting based on this frost date — see the calendar above for exact timing.
What planting zone is Amador County, CA?
Amador County, California is in USDA Hardiness Zone 9b. The average last spring frost is March 8 and first fall frost is November 25.
Your Amador County Garden Planner — Free
A 24-page printable planner built for Amador County (Zone 9b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.