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When to Plant Komatsuna in Jackson County, TX

Jackson County, Texas Zone 9b May

Top priorities for Jackson County, Texas gardeners in May

May rewards gardeners who work with the weather, not against it. Here's how to stay in step this month in Jackson County, Texas.

Avg. last frost February 21
Avg. first frost December 5
Soil temp (4") 76°F
Watering Low
Pest pressure High
Daylight 13.4 hrs
  1. It's harvest week for komatsuna

    Morning harvests are best — cooler temperatures mean crisper produce and longer fridge life.

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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.

Jackson County, Texas is in USDA Zone 9b. The average last spring frost is February 21 and the first fall frost is December 5, giving you a growing season of approximately 287 days.

At an elevation of 286 feet, Jackson County receives approximately 64.3 inches of rainfall annually with predominantly loam soil. Summer highs average 103°F, so Komatsuna may need afternoon shade and extra watering during peak heat. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Komatsuna root diseases.

Jackson County, TX (Zone 9b) Year-round
287 days
Last Spring Frost February 21
287 growing days
First Fall Frost December 5
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Jackson County Soil Profile

Soil Type

Loam

Soil pH

6.5-7.2

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (219 days to spare)
Start indoors: Jan 11 Transplant: Feb 8 🍅 Harvest: Mar 15 – Apr 19
Recommended (50%) ✓ Fits season (217 days to spare)
Start indoors: Jan 24 Transplant: Feb 21 🍅 Harvest: Mar 28 – May 2
Safe Start (90%) ✓ Fits season (209 days to spare)
Start indoors: Feb 14 Transplant: Mar 14 🍅 Harvest: Apr 18 – May 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 Jackson County

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

Soil pH

Your soil pH (6.5–7.2) is within Komatsuna's preferred range (6.0–7.5).

Soil Texture

The loam soil in Jackson County is excellent for Komatsuna — good drainage, moisture retention, and nutrient holding capacity.

Drainage

Drainage is adequate for Komatsuna.

Organic Matter

Organic matter is moderate (2.0%). Annual compost additions will help Komatsuna.

How to Plant Komatsuna

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

Fall planting: Sow 8 weeks before your first frost date for a fall harvest.

Succession Planting Komatsuna

10
successive plantings in your 287-day season

Sow every 4 weeks. Last sowing by Oct 16 to harvest before frost.

For a dedicated fall crop, sow by Oct 10.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.9″/week
You supply
0.4″/week
Watering frequency 1-2 times/week
Season total 929 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 1.7" 0" ❄️ Dormant
Feb 4.3" 2.1" 2.2" 🚿 Regular watering
Mar 4.3" 3.9" 0.4" 💧 Light watering
Apr 4.3" 6.5" 0" ✅ Rainfall sufficient
May 4.3" 9" 0" ✅ Rainfall sufficient
Jun 4.3" 10.4" 0" ✅ Rainfall sufficient
Jul 4.3" 7.9" 0" ✅ Rainfall sufficient
Aug 4.3" 8" 0" ✅ Rainfall sufficient
Sep 4.3" 6" 0" ✅ Rainfall sufficient
Oct 4.3" 4.8" 0" ✅ Rainfall sufficient
Nov 4.3" 2.3" 2" 💧 Light watering
Dec 4.3" 1.7" 2.6" 🚿 Regular watering

Water needs are for active growing months only (Feb–Dec in Jackson 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 needs ~1,158 GDD — county provides 7,848 GDD Excellent fit

Komatsuna Planting Timeline — Jackson County, TX

Komatsuna Planting Calendar

Activity When Date Range
Start Indoors January 24 Jan 24 – Feb 7
Transplant Outdoors February 21 Feb 21 – Mar 7
Direct Sow January 31 Jan 31 – Feb 21
Harvest March 28 Mar 28 – May 2
Fall Sowing October 10 Oct 10 – Oct 24

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

Month-by-Month Timeline

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

☀️ Sun

Partial Shade (3-6 hours)

💧 Water

1"/week · 1-2 times/week

📅 Days to Maturity

35–50 days

🧪 Soil pH

Needs 6–7.5 · Your soil: ideal

🗺️ USDA Zone

Zone 9b

📆 Growing Season

287 days in Jackson County

Growing Tips for Komatsuna in Jackson County

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

With summer highs reaching 103°F in Jackson County, provide afternoon shade for Komatsuna and water deeply in the morning.

Your generous 288.0-day season in Jackson 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 Jackson County, TX?

Jackson County is in Zone 9b with an average last frost of February 21. Plan your Komatsuna planting based on this frost date — see the calendar above for exact timing.

What planting zone is Jackson County, TX?

Jackson County, Texas is in USDA Hardiness Zone 9b. The average last spring frost is February 21 and first fall frost is December 5.

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Your Jackson County Garden Planner — Free

A 24-page printable planner built for Jackson County (Zone 9b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

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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 Jackson County, TX. Local conditions may vary. Last updated: May 2026.

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.