When to Plant Spinach in San Juan County, NM
Your April game plan for San Juan County, New Mexico
April rewards gardeners who work with the weather, not against it. Here's how to stay in step this month in San Juan County, New Mexico.
-
Put spinach seeds straight in the ground
Thin ruthlessly once seedlings are up. Crowded roots mean smaller crops from every plant.
A few tasks this April that'll pay off in May
- Transplants going out: 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.
San Juan County, New Mexico is in USDA Zone 5b. The average last spring frost is May 12 and the first fall frost is October 6, giving you a growing season of approximately 147 days.
At an elevation of 8,301 feet, San Juan County receives approximately 14.3 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 87°F, providing good warmth for Spinach during the growing season. Sandy soil warms quickly in spring — great for early planting — but Spinach will need more frequent watering and organic matter to retain nutrients. With low rainfall, drip irrigation is essential for growing Spinach successfully. Mulch heavily to conserve soil moisture.
San Juan County Soil Profile
Soil Type
Sandy Loam
Soil pH
7.3-8.5
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 San Juan County
How your county's soil matches Spinach's growing requirements.
Soil pH
Your soil pH (7.3–8.5) is more alkaline than Spinach prefers (6.5–7.5). Add sulfur or peat moss to lower pH.
Soil Texture
Sandy soil in San Juan County warms quickly in spring but drains fast. Spinach will need more frequent watering and regular compost additions to retain nutrients.
Drainage
Drainage is adequate for Spinach.
Organic Matter
Organic matter is low (0.9%). Add 2-3 inches of compost before planting 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 Aug 17 to harvest before frost.
For a dedicated fall crop, sow by Jul 28.
Plant Water Budget
Water stress score is 10/10 — 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 | — | 1.1" | 0" | ❄️ Dormant |
| Feb | — | 0.8" | 0" | ❄️ Dormant |
| Mar | — | 0.8" | 0" | ❄️ Dormant |
| Apr | — | 0.5" | 0" | ❄️ Dormant |
| May | 3" | 0.3" | 2.7" | 🚿 Regular watering |
| Jun | 3" | 0.5" | 2.5" | 🚿 Regular watering |
| Jul | 3" | 2.5" | 0.5" | 💧 Light watering |
| Aug | 3" | 2.6" | 0.4" | 💧 Light watering |
| Sep | 3" | 2.2" | 0.8" | 💧 Light watering |
| Oct | 3" | 1.3" | 1.7" | 🚿 Regular watering |
| Nov | — | 0.8" | 0" | ❄️ Dormant |
| Dec | — | 0.9" | 0" | ❄️ Dormant |
Water needs are for active growing months only (May–Oct in San Juan 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 — San Juan County, NM
Spinach Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | April 7 | Apr 7 – Apr 21 |
| Transplant Outdoors | May 12 | May 12 – May 26 |
| Direct Sow | April 28 | Apr 28 – May 19 |
| Harvest | June 16 | Jun 16 – Aug 18 |
| Fall Sowing | July 28 | Jul 28 – Aug 11 |
Plant 0.5" deep · 6" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | — |
| April | Start Indoors Direct Sow |
| May | Transplant Outdoors Direct Sow |
| June | Harvest |
| July | Fall Sowing Harvest |
| August | Fall Sowing Harvest |
| September | — |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Partial Shade (3-6 hours)
💧 Water
0.7"/week · 1-2 times/week
📅 Days to Maturity
35–50 days
🧪 Soil pH
Needs 6.5–7.5 · Your soil: too_alkaline
🗺️ USDA Zone
Zone 5b
📆 Growing Season
147 days in San Juan County
Growing Tips for Spinach in San Juan County
Direct sow Spinach outdoors after May 12 in San Juan County when soil has warmed and frost danger has passed.
Sandy soil in San Juan County dries quickly — mulch Spinach with 2-3 inches of straw and water deeply 2-3 times per week rather than lightly every day.
Your generous 147.0-day season in San Juan 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 San Juan 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 San Juan County, NM?
San Juan County is in Zone 5b with an average last frost of May 12. Plan your Spinach planting based on this frost date — see the calendar above for exact timing.
What planting zone is San Juan County, NM?
San Juan County, New Mexico is in USDA Hardiness Zone 5b. The average last spring frost is May 12 and first fall frost is October 6.
Your San Juan County Garden Planner — Free
A 24-page printable planner built for San Juan County (Zone 5b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.