When to Plant Napa Cabbage in Ada County, ID
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.
Ada County, Idaho is in USDA Zone 6b. The average last spring frost is April 23 and the first fall frost is October 16, giving you a growing season of approximately 176 days.
At an elevation of 4,372 feet, Ada County receives approximately 19.8 inches of rainfall annually with predominantly loam soil. Summer highs average 90°F, providing good warmth for Napa Cabbage during the growing season. With low rainfall, drip irrigation is essential for growing Napa Cabbage successfully. Mulch heavily to conserve soil moisture.
Ada County Soil Profile
Soil Type
Loam
Soil pH
6.4-7.7
Drainage
Well Drained
Monthly Watering Guide for Napa Cabbage
Napa Cabbage needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.
| Month | Napa Cabbage Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 1.4" | 0" | ❄️ Dormant |
| Feb | — | 1.2" | 0" | ❄️ Dormant |
| Mar | — | 1.5" | 0" | ❄️ Dormant |
| Apr | 4.3" | 2" | 2.3" | 🚿 Regular watering |
| May | 4.3" | 2.4" | 1.9" | 💧 Light watering |
| Jun | 4.3" | 1.4" | 2.9" | 🚿 Regular watering |
| Jul | 4.3" | 1.8" | 2.5" | 🚿 Regular watering |
| Aug | 4.3" | 2.4" | 1.9" | 💧 Light watering |
| Sep | 4.3" | 1.5" | 2.8" | 🚿 Regular watering |
| Oct | 4.3" | 1.8" | 2.5" | 🚿 Regular watering |
| Nov | — | 1.3" | 0" | ❄️ Dormant |
| Dec | — | 1.2" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Oct in Ada County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Napa Cabbage Planting Timeline — Ada County, ID
Napa Cabbage Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | March 19 | Mar 19 – Apr 2 |
| Transplant Outdoors | April 23 | Apr 23 – May 7 |
| Direct Sow | April 9 | Apr 9 – Apr 30 |
| Harvest | June 18 | Jun 18 – Jul 23 |
| Fall Sowing | August 7 | Aug 7 – Aug 21 |
Plant 1" deep · 15" apart · Rows 24" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | Start Indoors |
| April | Start Indoors Transplant Outdoors Direct Sow |
| May | Transplant Outdoors |
| June | Harvest |
| July | Harvest |
| August | Fall Sowing |
| September | — |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Partial Shade (3-6 hours)
💧 Water
High — keep soil consistently moist
📅 Days to Maturity
55–75 days
🧪 Soil pH
Needs 6–7.5 · Your soil: N/A
🗺️ USDA Zone
Zone 6b
📆 Growing Season
176 days in Ada County
Growing Tips for Ada County
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
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Napa Cabbage in Other Locations
Frequently Asked Questions
When should I plant Napa Cabbage in Ada County, ID?
Ada County is in Zone 6b with an average last frost of April 23. Plan your Napa Cabbage planting based on this frost date — see the calendar above for exact timing.
What planting zone is Ada County, ID?
Ada County, Idaho is in USDA Hardiness Zone 6b. The average last spring frost is April 23 and first fall frost is October 16.
Plan Your Garden with Confidence
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