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When to Plant Komatsuna in Polk County, TN

Polk County, Tennessee Zone 7a April

What to do in April

We've pulled the most time-sensitive tasks for Polk County, Tennessee this April and put them front and centre. Tackle them in order.

Avg. last frost April 19
Avg. first frost October 19
Soil temp (4") 58°F
Watering Moderate
Pest pressure Moderate
Daylight 12.9 hrs
  1. Plant out komatsuna

    Bring a watering can to the bed. Each transplant gets a drink the moment it's in the ground, not ten minutes later.

  2. Scatter komatsuna into prepared beds

    Rake a smooth bed, make a shallow furrow, drop seeds at the spacing on the packet, water gently, walk away.

To set up a strong May, finish these tasks
  • Starting indoors: komatsuna
  • First harvests: komatsuna

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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.

Polk County, Tennessee is in USDA Zone 7a. The average last spring frost is April 19 and the first fall frost is October 19, giving you a growing season of approximately 183 days.

At an elevation of 1,255 feet, Polk County receives approximately 43.6 inches of rainfall annually with predominantly silt loam soil. Summer highs average 91°F, providing good warmth for Komatsuna during the growing season.

Polk County, TN (Zone 7a) Moderate season
183 days
Last Spring Frost April 19
183 growing days
First Fall Frost October 19

Polk County Soil Profile

Soil Type

Silt Loam

Soil pH

5.4-6.5

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (119 days to spare)
Start indoors: Mar 6 Transplant: Apr 10 🍅 Harvest: May 15 – Jun 19
Recommended (50%) ✓ Fits season (113 days to spare)
Start indoors: Mar 15 Transplant: Apr 19 🍅 Harvest: May 24 – Jun 28
Safe Start (90%) ✓ Fits season (110 days to spare)
Start indoors: Mar 31 Transplant: May 5 🍅 Harvest: Jun 9 – Jul 14

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 Polk County

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

Soil pH

Your soil pH (5.4–6.5) is more acidic than Komatsuna prefers (6.0–7.5). Add garden lime to raise pH.

Soil Texture

The silt loam soil in Polk 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 (2.5%). 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 183-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
1.0″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft
Drought risk

Water stress score is 6/10 — 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 3.4" 0" ❄️ Dormant
Feb 3.8" 0" ❄️ Dormant
Mar 4.1" 0" ❄️ Dormant
Apr 4.3" 3.7" 0.6" 💧 Light watering
May 4.3" 3.9" 0.4" 💧 Light watering
Jun 4.3" 4.3" 0" ✅ Rainfall sufficient
Jul 4.3" 4" 0.3" 💧 Light watering
Aug 4.3" 3.7" 0.6" 💧 Light watering
Sep 4.3" 3.3" 1" 💧 Light watering
Oct 4.3" 2.6" 1.7" 💧 Light watering
Nov 2.9" 0" ❄️ Dormant
Dec 3.8" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Polk 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 ~776 GDD — county provides 3,339 GDD Excellent fit

Komatsuna Planting Timeline — Polk County, TN

Komatsuna Planting Calendar

Activity When Date Range
Start Indoors March 15 Mar 15 – Mar 29
Transplant Outdoors April 19 Apr 19 – May 3
Direct Sow April 5 Apr 5 – Apr 26
Harvest May 24 May 24 – Jun 28
Fall Sowing August 10 Aug 10 – Aug 24

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Partial Shade (3-6 hours)

💧 Water

1"/week · Natural rainfall sufficient

📅 Days to Maturity

35–50 days

🧪 Soil pH

Needs 6–7.5 · Your soil: too_acidic

🗺️ USDA Zone

Zone 7a

📆 Growing Season

183 days in Polk County

Growing Tips for Komatsuna in Polk County

Direct sow Komatsuna outdoors after April 19 in Polk County when soil has warmed and frost danger has passed.

Your generous 183.0-day season in Polk 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 Polk County, TN?

Polk County is in Zone 7a with an average last frost of April 19. Plan your Komatsuna planting based on this frost date — see the calendar above for exact timing.

What planting zone is Polk County, TN?

Polk County, Tennessee is in USDA Hardiness Zone 7a. The average last spring frost is April 19 and first fall frost is October 19.

🌱

Your Polk County Garden Planner — Free

A 24-page printable planner built for Polk County (Zone 7a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

Instant PDF download. No spam, unsubscribe any time.

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

Sources & credits

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