When to Plant Komatsuna in Duchesne County, UT
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.
Duchesne County, Utah is in USDA Zone 4b. The average last spring frost is May 10 and the first fall frost is October 4, giving you a growing season of approximately 147 days.
At an elevation of 5,302 feet, Duchesne County receives approximately 13 inches of rainfall annually with predominantly loam soil. Summer highs average 80°F, so choose short-season varieties of Komatsuna to ensure they mature before fall. With low rainfall, drip irrigation is essential for growing Komatsuna successfully. Mulch heavily to conserve soil moisture.
Duchesne County Soil Profile
Soil Type
Loam
Soil pH
6.4-8.2
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 Duchesne County
How your county's soil matches Komatsuna's growing requirements.
Soil pH
Your soil pH (6.4–8.2) overlaps with Komatsuna's range (6.0–7.5), though not a perfect match.
Soil Texture
The loam soil in Duchesne County is excellent for Komatsuna — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is moderate (2.5%). Annual compost additions will help Komatsuna.
How to Plant Komatsuna
Fall planting: Sow 12 weeks before your first frost date for a fall harvest.
Succession Planting Komatsuna
Sow every 4 weeks. Last sowing by Aug 15 to harvest before frost.
For a dedicated fall crop, sow by Jul 12.
Plant Water Budget
Water stress score is 8/10 — consider drought-tolerant varieties and mulching
Monthly Watering Guide for Komatsuna
Komatsuna needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.
| Month | Komatsuna Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 0.9" | 0" | ❄️ Dormant |
| Feb | — | 0.8" | 0" | ❄️ Dormant |
| Mar | — | 1.3" | 0" | ❄️ Dormant |
| Apr | — | 1.4" | 0" | ❄️ Dormant |
| May | 4.3" | 1.3" | 3" | 🚿 Regular watering |
| Jun | 4.3" | 0.8" | 3.5" | 🚿 Regular watering |
| Jul | 4.3" | 1.3" | 3" | 🚿 Regular watering |
| Aug | 4.3" | 1.3" | 3" | 🚿 Regular watering |
| Sep | 4.3" | 1.2" | 3.1" | 🚿 Regular watering |
| Oct | 4.3" | 1.3" | 3" | 🚿 Regular watering |
| Nov | — | 1" | 0" | ❄️ Dormant |
| Dec | — | 0.6" | 0" | ❄️ Dormant |
Water needs are for active growing months only (May–Oct in Duchesne County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Komatsuna 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.
Komatsuna Planting Timeline — Duchesne County, UT
Komatsuna Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | March 29 | Mar 29 – Apr 12 |
| Transplant Outdoors | May 10 | May 10 – May 24 |
| Direct Sow | May 3 | May 3 – May 24 |
| Harvest | June 14 | Jun 14 – Jul 19 |
| Fall Sowing | July 12 | Jul 12 – Jul 26 |
Plant 0.5" deep · 6" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | Start Indoors |
| April | Start Indoors |
| May | Transplant Outdoors Direct Sow |
| June | Harvest |
| July | Fall Sowing Harvest |
| August | — |
| September | — |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Partial Shade (3-6 hours)
💧 Water
1"/week · 2-3 times/week
📅 Days to Maturity
35–50 days
🧪 Soil pH
Needs 6–7.5 · Your soil: acceptable
🗺️ USDA Zone
Zone 4b
📆 Growing Season
147 days in Duchesne County
Growing Tips for Komatsuna in Duchesne County
Direct sow Komatsuna outdoors after May 10 in Duchesne County when soil has warmed and frost danger has passed.
Your generous 147.0-day season in Duchesne County allows multiple plantings of Komatsuna. Sow every 17.0 days for continuous harvest.
Common pests for Komatsuna in this region include cabbage worm and flea beetles. Use row covers early in the season and inspect plants weekly.
Duchesne County receives only 13" of rain annually. Komatsuna needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.
General growing tips
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
Check more plant combinations with our Companion Planting Checker →
Komatsuna in Other Locations
Frequently Asked Questions
When should I plant Komatsuna in Duchesne County, UT?
Duchesne County is in Zone 4b with an average last frost of May 10. Plan your Komatsuna planting based on this frost date — see the calendar above for exact timing.
What planting zone is Duchesne County, UT?
Duchesne County, Utah is in USDA Hardiness Zone 4b. The average last spring frost is May 10 and first fall frost is October 4.
Plan Your Garden with Confidence
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