When to Plant Napa Cabbage in San Miguel County, CO
Your May planting checklist for San Miguel County, Colorado
Your San Miguel County, Colorado garden is entering a new phase. Here's what's on the schedule for May and why each task matters now.
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Move napa cabbage from tray to bed
Water the tray well an hour before you transplant. Roots slide out cleanly and settle in faster.
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Seed napa cabbage outdoors
Keep the top inch of soil moist until germination — a gentle morning watering for 5–7 days does the job.
Napa cabbage forms tall, barrel-shaped heads with tender, crinkled leaves and a mild, slightly sweet flavor. It is the primary cabbage used for kimchi.
San Miguel County, Colorado is in USDA Zone 5b. The average last spring frost is May 31 and the first fall frost is September 21, giving you a growing season of approximately 113 days.
At an elevation of 8,402 feet, San Miguel County receives approximately 21.6 inches of rainfall annually with predominantly loam soil. Summer highs average 85°F, providing good warmth for Napa Cabbage during the growing season.
San Miguel County Soil Profile
Soil Type
Loam
Soil pH
6.8-7.6
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 Miguel County
How your county's soil matches Napa Cabbage's growing requirements.
Soil pH
Your soil pH (6.8–7.6) overlaps with Napa Cabbage's range (6.0–7.5), though not a perfect match.
Soil Texture
The loam soil in San Miguel County is excellent for Napa Cabbage — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is moderate (2.3%). Annual compost additions will help Napa Cabbage.
How to Plant Napa Cabbage
Fall planting: Sow 10 weeks before your first frost date for a fall harvest.
Succession Planting Napa Cabbage
Sow every 6.3 weeks. Last sowing by Jul 08 to harvest before frost.
For a dedicated fall crop, sow by Jul 13.
Plant Water Budget
Water stress score is 8/10 — consider drought-tolerant varieties and mulching
Monthly Watering Guide for Napa Cabbage
Napa Cabbage needs approximately 1.5 inches of water per week (6.5" per month). Here's how your county's rainfall compares month by month.
| Month | Napa Cabbage Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 1.6" | 0" | ❄️ Dormant |
| Feb | — | 1.4" | 0" | ❄️ Dormant |
| Mar | — | 2.1" | 0" | ❄️ Dormant |
| Apr | — | 2.4" | 0" | ❄️ Dormant |
| May | 6.5" | 2.6" | 3.9" | 🚿 Regular watering |
| Jun | 6.5" | 1.4" | 5.1" | 🚿 Regular watering |
| Jul | 6.5" | 1.7" | 4.8" | 🚿 Regular watering |
| Aug | 6.5" | 2.5" | 4" | 🚿 Regular watering |
| Sep | 6.5" | 1.5" | 5" | 🚿 Regular watering |
| Oct | — | 1.7" | 0" | ❄️ Dormant |
| Nov | — | 1.3" | 0" | ❄️ Dormant |
| Dec | — | 1.3" | 0" | ❄️ Dormant |
Water needs are for active growing months only (May–Sep in San Miguel County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Napa Cabbage 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.
Napa Cabbage Planting Timeline — San Miguel County, CO
Napa Cabbage Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | April 26 | Apr 26 – May 10 |
| Transplant Outdoors | May 31 | May 31 – Jun 14 |
| Direct Sow | May 17 | May 17 – Jun 7 |
| Harvest | July 26 | Jul 26 – Aug 30 |
| Fall Sowing | July 13 | Jul 13 – Jul 27 |
Plant 1" deep · 15" apart · Rows 24" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | — |
| April | Start Indoors |
| May | Start Indoors Transplant Outdoors Direct Sow |
| June | Transplant Outdoors Direct Sow |
| July | Fall Sowing Harvest |
| August | Harvest |
| September | — |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Partial Shade (3-6 hours)
💧 Water
1.5"/week · 2-3 times/week
📅 Days to Maturity
55–75 days
🧪 Soil pH
Needs 6–7.5 · Your soil: acceptable
🗺️ USDA Zone
Zone 5b
📆 Growing Season
113 days in San Miguel County
Growing Tips for Napa Cabbage in San Miguel County
Direct sow Napa Cabbage outdoors after May 31 in San Miguel County when soil has warmed and frost danger has passed.
Common pests for Napa Cabbage in this region include cabbage worm and flea beetles. Use row covers early in the season and inspect plants weekly.
San Miguel County receives only 22" of rain annually. Napa Cabbage needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.
General growing tips
Best grown as a fall crop. Direct sow in late summer, 60-70 days before first frost. Keep soil evenly moist. Bolt-resistant varieties are available for spring planting.
Companion Planting
Good Companions
Avoid Planting Near
Check more plant combinations with our Companion Planting Checker →
Napa Cabbage in Other Locations
Frequently Asked Questions
When should I plant Napa Cabbage in San Miguel County, CO?
San Miguel County is in Zone 5b with an average last frost of May 31. Plan your Napa Cabbage planting based on this frost date — see the calendar above for exact timing.
What planting zone is San Miguel County, CO?
San Miguel County, Colorado is in USDA Hardiness Zone 5b. The average last spring frost is May 31 and first fall frost is September 21.
Your San Miguel County Garden Planner — Free
A 24-page printable planner built for San Miguel 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.