When to Plant Komatsuna in Navajo County, AZ
Komatsuna (Japanese mustard spinach) is a versatile Asian green with glossy, dark leaves and a mild, sweet flavor. It is extremely cold-hardy and heat-tolerant.
Navajo County, Arizona is in USDA Zone 6a. The average last spring frost is May 2 and the first fall frost is October 16, giving you a growing season of approximately 167 days.
At an elevation of 5,528 feet, Navajo County receives approximately 15.8 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 94°F, providing good warmth for Komatsuna during the growing season. Sandy soil warms quickly in spring — great for early planting — but Komatsuna will need more frequent watering and organic matter to retain nutrients. With low rainfall, drip irrigation is essential for growing Komatsuna successfully. Mulch heavily to conserve soil moisture.
Navajo County Soil Profile
Soil Type
Sandy Loam
Soil pH
7.3-8.3
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.
Plant Water Budget
Water stress score is 10/10 — consider drought-tolerant varieties and mulching
Komatsuna Planting Timeline — Navajo County, AZ
Komatsuna Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | March 28 | Mar 28 – Apr 11 |
| Transplant Outdoors | May 2 | May 2 – May 16 |
| Direct Sow | April 18 | Apr 18 – May 9 |
| Fall Sowing | August 7 | Aug 7 – Aug 21 |
| Harvest | June 6 | Jun 6 – Jul 11 |
Plant 0.5" deep · 6" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | Start Indoors |
| April | Start Indoors Direct Sow |
| May | Transplant Outdoors Direct Sow |
| June | Harvest |
| July | Harvest |
| August | Fall Sowing |
| September | — |
| October | — |
| November | — |
| December | — |
Growing Conditions
Sun
Partial Shade (3-6 hours)
Water
Moderate — regular watering
Days to Maturity
35–50 days
Soil pH
6 – 7.5
USDA Zone
Zone 6a
Growing Season
167 days
Growing Tips for Navajo County
Direct sow in spring or fall. One of the most forgiving Asian greens for all seasons. Harvest outer leaves or cut whole plants. Excellent for stir-fries, soups, or salads.
Companion Planting
Good Companions
Avoid Planting Near
Level Up Your Garden
Komatsuna in Other Locations
Frequently Asked Questions
When should I plant Komatsuna in Navajo County, AZ?
Navajo County is in Zone 6a with an average last frost of May 2. Plan your Komatsuna planting based on this frost date — see the calendar above for exact timing.
What planting zone is Navajo County, AZ?
Navajo County, Arizona is in USDA Hardiness Zone 6a. The average last spring frost is May 2 and first fall frost is October 16.
Plan Your Garden with Confidence
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