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When to Plant Komatsuna in Pinellas County, FL

Pinellas County, Florida Zone 10a May

Your May game plan for Pinellas County, Florida

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Avg. last frost January 25
Avg. first frost December 16
Soil temp (4") 77°F
Watering Moderate
Pest pressure High
Daylight 13.4 hrs

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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.

Pinellas County, Florida is in USDA Zone 10a. The average last spring frost is January 25 and the first fall frost is December 16, giving you a growing season of approximately 325 days.

At an elevation of 246 feet, Pinellas County receives approximately 58.1 inches of rainfall annually with predominantly sand soil. Summer highs average 102°F, so Komatsuna may need afternoon shade and extra watering during peak heat. Sandy soil warms quickly in spring — great for early planting — but Komatsuna will need more frequent watering and organic matter to retain nutrients. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Komatsuna root diseases.

Pinellas County, FL (Zone 10a) Year-round
325 days
Last Spring Frost January 25
325 growing days
First Fall Frost December 16
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Pinellas County Soil Profile

Soil Type

Sand

Soil pH

5.1-6.2

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (255 days to spare)
Start indoors: Dec 22 Transplant: Jan 19 🍅 Harvest: Feb 23 – Mar 30
Recommended (50%) ✓ Fits season (255 days to spare)
Start indoors: Dec 28 Transplant: Jan 25 🍅 Harvest: Mar 1 – Apr 5
Safe Start (90%) ✓ Fits season (229 days to spare)
Start indoors: Jan 31 Transplant: Feb 28 🍅 Harvest: Apr 4 – May 9

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 Pinellas County

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

Soil pH

Your soil pH (5.1–6.2) is more acidic than Komatsuna prefers (6.0–7.5). Add garden lime to raise pH.

Soil Texture

Sandy soil in Pinellas County warms quickly in spring but drains fast. Komatsuna will need more frequent watering and regular compost additions to retain nutrients.

Drainage

Drainage is adequate for Komatsuna.

Organic Matter

Organic matter is low (1.5%). Add 2-3 inches of compost before planting 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

11
successive plantings in your 325-day season

Sow every 4 weeks. Last sowing by Oct 27 to harvest before frost.

For a dedicated fall crop, sow by Oct 21.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.8″/week
You supply
0.6″/week
Watering frequency 1-2 times/week
Season total 1,600 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 4.3" 2.9" 1.4" 💧 Light watering
Feb 4.3" 3.2" 1.1" 💧 Light watering
Mar 4.3" 3.7" 0.6" 💧 Light watering
Apr 4.3" 2.4" 1.9" 💧 Light watering
May 4.3" 3.6" 0.7" 💧 Light watering
Jun 4.3" 7.6" 0" ✅ Rainfall sufficient
Jul 4.3" 8.5" 0" ✅ Rainfall sufficient
Aug 4.3" 8.7" 0" ✅ Rainfall sufficient
Sep 4.3" 7.1" 0" ✅ Rainfall sufficient
Oct 4.3" 5.3" 0" ✅ Rainfall sufficient
Nov 4.3" 2.5" 1.8" 💧 Light watering
Dec 4.3" 2.6" 1.7" 💧 Light watering

Water needs are for active growing months only (Jan–Dec in Pinellas 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 ~1,126 GDD — county provides 8,639 GDD Excellent fit

Komatsuna Planting Timeline — Pinellas County, FL

Komatsuna Planting Calendar

Activity When Date Range
Start Indoors December 28 Dec 28 – Jan 11
Transplant Outdoors January 25 Jan 25 – Feb 8
Direct Sow January 4 Jan 4 – Jan 25
Harvest March 1 Mar 1 – Apr 5
Fall Sowing October 21 Oct 21 – Nov 4

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

Month-by-Month Timeline

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

🗺️ USDA Zone

Zone 10a

📆 Growing Season

325 days in Pinellas County

Growing Tips for Komatsuna in Pinellas County

Direct sow Komatsuna outdoors after January 25 in Pinellas County when soil has warmed and frost danger has passed.

Sandy soil in Pinellas County dries quickly — mulch Komatsuna with 2-3 inches of straw and water deeply 2-3 times per week rather than lightly every day.

With summer highs reaching 102°F in Pinellas County, provide afternoon shade for Komatsuna and water deeply in the morning.

Your generous 326.0-day season in Pinellas 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 Pinellas County, FL?

Pinellas County is in Zone 10a with an average last frost of January 25. Plan your Komatsuna planting based on this frost date — see the calendar above for exact timing.

What planting zone is Pinellas County, FL?

Pinellas County, Florida is in USDA Hardiness Zone 10a. The average last spring frost is January 25 and first fall frost is December 16.

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Your Pinellas County Garden Planner — Free

A 24-page printable planner built for Pinellas County (Zone 10a). 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 Pinellas County, FL. 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.