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When to Plant Komatsuna in Davis 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.

Davis County, Utah is in USDA Zone 6b. The average last spring frost is May 6 and the first fall frost is October 10, giving you a growing season of approximately 157 days.

At an elevation of 4,567 feet, Davis County receives approximately 16.6 inches of rainfall annually with predominantly loam soil. Summer highs average 91ยฐF, providing good warmth for Komatsuna during the growing season. With low rainfall, drip irrigation is essential for growing Komatsuna successfully. Mulch heavily to conserve soil moisture.

Davis County, UT (Zone 6b) Moderate season
157 days
Last Spring Frost May 6
157 growing days
First Fall Frost October 10

Davis County Soil Profile

Soil Type

Loam

Soil pH

6.5-7.6

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (86 days to spare)
Start indoors: Mar 22 Transplant: Apr 26 🍅 Harvest: May 31 – Jul 5
Recommended (50%) ✓ Fits season (87 days to spare)
Start indoors: Apr 1 Transplant: May 6 🍅 Harvest: Jun 10 – Jul 15
Safe Start (90%) ✓ Fits season (71 days to spare)
Start indoors: May 6 Transplant: Jun 10 🍅 Harvest: Jul 15 – Aug 19

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 Davis County

How your county's soil matches Komatsuna's growing requirements.

Soil pH

Your soil pH (6.5โ€“7.6) overlaps with Komatsuna's range (6.0โ€“7.5), though not a perfect match.

Soil Texture

The loam soil in Davis County is excellent for Komatsuna โ€” good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is moderate (2.1%). Annual compost additions will help Komatsuna.

How to Plant Komatsuna

0.5"
Planting Depth
6"
Between Plants
12"
Between Rows

Fall planting: Sow 10 weeks before your first frost date for a fall harvest.

Succession Planting Komatsuna

5
successive plantings in your 157-day season

Sow every 4 weeks. Last sowing by Aug 21 to harvest before frost.

For a dedicated fall crop, sow by Aug 01.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.4″/week
You supply
0.7″/week
Watering frequency 1-2 times/week
Season total 932 gal / 100 sq ft
Drought risk

Water stress score is 10/10 โ€” 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 โ€” 1.2" 0" โ„๏ธ Dormant
Feb โ€” 1.1" 0" โ„๏ธ Dormant
Mar โ€” 1.2" 0" โ„๏ธ Dormant
Apr โ€” 1.9" 0" โ„๏ธ Dormant
May 4.3" 1.7" 2.6" ๐Ÿšฟ Regular watering
Jun 4.3" 1" 3.3" ๐Ÿšฟ Regular watering
Jul 4.3" 1.7" 2.6" ๐Ÿšฟ Regular watering
Aug 4.3" 2" 2.3" ๐Ÿšฟ Regular watering
Sep 4.3" 1.5" 2.8" ๐Ÿšฟ Regular watering
Oct 4.3" 1.4" 2.9" ๐Ÿšฟ Regular watering
Nov โ€” 1.2" 0" โ„๏ธ Dormant
Dec โ€” 0.9" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Mayโ€“Oct in Davis County). Supplement amounts are based on average rainfall โ€” 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" โ€” every day above 50ยฐF 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 needs ~776 GDD — county provides 2,865 GDD Excellent fit

Komatsuna Planting Timeline โ€” Davis County, UT

Komatsuna Planting Calendar

Activity When Date Range
Start Indoors April 1 Apr 1 โ€“ Apr 15
Transplant Outdoors May 6 May 6 โ€“ May 20
Direct Sow April 22 Apr 22 โ€“ May 13
Harvest June 10 Jun 10 โ€“ Jul 15
Fall Sowing August 1 Aug 1 โ€“ Aug 15

Plant 0.5" deep ยท 6" apart ยท Rows 12" apart

Month-by-Month Timeline

MonthActivities
January โ€”
February โ€”
March โ€”
April Start Indoors Direct Sow
May Transplant Outdoors Direct Sow
June Harvest
July Harvest
August Fall Sowing
September โ€”
October โ€”
November โ€”
December โ€”

Growing Conditions

โ˜€๏ธ Sun

Partial Shade (3-6 hours)

๐Ÿ’ง Water

1"/week ยท 1-2 times/week

๐Ÿ“… Days to Maturity

35โ€“50 days

๐Ÿงช Soil pH

Needs 6โ€“7.5 ยท Your soil: acceptable

๐Ÿ—บ๏ธ USDA Zone

Zone 6b

๐Ÿ“† Growing Season

157 days in Davis County

Growing Tips for Komatsuna in Davis County

Direct sow Komatsuna outdoors after May 06 in Davis County when soil has warmed and frost danger has passed.

Your generous 157.0-day season in Davis 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.

Davis County receives only 17" of rain annually. Komatsuna needs consistent moisture โ€” 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

  • Strawberries

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Komatsuna in Davis County, UT?

Davis County is in Zone 6b with an average last frost of May 6. Plan your Komatsuna planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Davis County, UT?

Davis County, Utah is in USDA Hardiness Zone 6b. The average last spring frost is May 6 and first fall frost is October 10.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Davis County gardeners in Zone 6b organize planting dates, track what's growing, and never miss a planting window.

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Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Davis County, UT. Local conditions may vary. Last updated: April 2026.