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When to Plant Komatsuna in Rappahannock County, VA

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.

Rappahannock County, Virginia is in USDA Zone 6b. The average last spring frost is April 21 and the first fall frost is October 19, giving you a growing season of approximately 181 days.

At an elevation of 370 feet, Rappahannock County receives approximately 46.9 inches of rainfall annually with predominantly silt loam soil. Summer highs average 87ยฐF, providing good warmth for Komatsuna during the growing season.

Rappahannock County, VA (Zone 6b) Moderate season
181 days
Last Spring Frost April 21
181 growing days
First Fall Frost October 19

Rappahannock County Soil Profile

Soil Type

Silt Loam

Soil pH

5.5-6.9

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (112 days to spare)
Start indoors: Mar 11 Transplant: Apr 15 🍅 Harvest: May 20 – Jun 24
Recommended (50%) ✓ Fits season (111 days to spare)
Start indoors: Mar 17 Transplant: Apr 21 🍅 Harvest: May 26 – Jun 30
Safe Start (90%) ✓ Fits season (101 days to spare)
Start indoors: Apr 9 Transplant: May 14 🍅 Harvest: Jun 18 – Jul 23

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 Rappahannock County

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

Soil pH

Your soil pH (5.5โ€“6.9) overlaps with Komatsuna's range (6.0โ€“7.5), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is moderate (3.3%). 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

6
successive plantings in your 181-day season

Sow every 4 weeks. Last sowing by Aug 30 to harvest before frost.

For a dedicated fall crop, sow by Aug 10.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
1.1″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft

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€” 3.9" 0" โ„๏ธ Dormant
Feb โ€” 4" 0" โ„๏ธ Dormant
Mar โ€” 4.4" 0" โ„๏ธ Dormant
Apr 4.3" 3.5" 0.8" ๐Ÿ’ง Light watering
May 4.3" 3.6" 0.7" ๐Ÿ’ง Light watering
Jun 4.3" 4.6" 0" โœ… Rainfall sufficient
Jul 4.3" 5.4" 0" โœ… Rainfall sufficient
Aug 4.3" 3.9" 0.4" ๐Ÿ’ง Light watering
Sep 4.3" 3.7" 0.6" ๐Ÿ’ง Light watering
Oct 4.3" 3.2" 1.1" ๐Ÿ’ง Light watering
Nov โ€” 3.2" 0" โ„๏ธ Dormant
Dec โ€” 3.4" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Aprโ€“Oct in Rappahannock 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 ~648 GDD — county provides 2,760 GDD Excellent fit

Komatsuna Planting Timeline โ€” Rappahannock County, VA

Komatsuna Planting Calendar

Activity When Date Range
Start Indoors March 17 Mar 17 โ€“ Mar 31
Transplant Outdoors April 21 Apr 21 โ€“ May 5
Direct Sow April 7 Apr 7 โ€“ Apr 28
Harvest May 26 May 26 โ€“ Jun 30
Fall Sowing August 10 Aug 10 โ€“ Aug 24

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

Month-by-Month Timeline

MonthActivities
January โ€”
February โ€”
March Start Indoors
April Transplant Outdoors Direct Sow
May Transplant Outdoors Harvest
June Harvest
July โ€”
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 Natural rainfall sufficient

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

181 days in Rappahannock County

Growing Tips for Komatsuna in Rappahannock County

Direct sow Komatsuna outdoors after April 21 in Rappahannock County when soil has warmed and frost danger has passed.

Your generous 181.0-day season in Rappahannock 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.

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 Rappahannock County, VA?

Rappahannock County is in Zone 6b with an average last frost of April 21. Plan your Komatsuna planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Rappahannock County, VA?

Rappahannock County, Virginia is in USDA Hardiness Zone 6b. The average last spring frost is April 21 and first fall frost is October 19.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Rappahannock 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 Rappahannock County, VA. Local conditions may vary. Last updated: April 2026.