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When to Plant Komatsuna in Indian River County, FL

Indian River County, Florida Zone 10a May

What to do in May

Your Indian River County, Florida garden is entering a new phase. Here's what's on the schedule for May and why each task matters now.

Avg. last frost January 26
Avg. first frost December 20
Soil temp (4") 78°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.

Indian River County, Florida is in USDA Zone 10a. The average last spring frost is January 26 and the first fall frost is December 20, giving you a growing season of approximately 328 days.

At an elevation of 317 feet, Indian River County receives approximately 52.7 inches of rainfall annually with predominantly sand soil. Summer highs average 97°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.

Indian River County, FL (Zone 10a) Year-round
328 days
Last Spring Frost January 26
328 growing days
First Fall Frost December 20
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Indian River County Soil Profile

Soil Type

Sand

Soil pH

5.2-6.2

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (256 days to spare)
Start indoors: Dec 22 Transplant: Jan 19 🍅 Harvest: Feb 23 – Mar 30
Recommended (50%) ✓ Fits season (258 days to spare)
Start indoors: Dec 29 Transplant: Jan 26 🍅 Harvest: Mar 2 – Apr 6
Safe Start (90%) ✓ Fits season (239 days to spare)
Start indoors: Jan 21 Transplant: Feb 18 🍅 Harvest: Mar 25 – Apr 29

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 Indian River County

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

Soil pH

Your soil pH (5.2–6.2) is more acidic than Komatsuna prefers (6.0–7.5). Add garden lime to raise pH.

Soil Texture

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

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 328-day season

Sow every 4 weeks. Last sowing by Oct 31 to harvest before frost.

For a dedicated fall crop, sow by Oct 25.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.7″/week
You supply
0.4″/week
Watering frequency 1-2 times/week
Season total 1,150 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 4.3" 2.5" 1.8" 💧 Light watering
Feb 4.3" 2.5" 1.8" 💧 Light watering
Mar 4.3" 2.8" 1.5" 💧 Light watering
Apr 4.3" 2.5" 1.8" 💧 Light watering
May 4.3" 3.3" 1" 💧 Light watering
Jun 4.3" 7.8" 0" ✅ Rainfall sufficient
Jul 4.3" 7.2" 0" ✅ Rainfall sufficient
Aug 4.3" 8.2" 0" ✅ Rainfall sufficient
Sep 4.3" 7.2" 0" ✅ Rainfall sufficient
Oct 4.3" 4.4" 0" ✅ Rainfall sufficient
Nov 4.3" 2.3" 2" 💧 Light watering
Dec 4.3" 1.9" 2.4" 🚿 Regular watering

Water needs are for active growing months only (Jan–Dec in Indian River 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 ~967 GDD — county provides 7,484 GDD Excellent fit

Komatsuna Planting Timeline — Indian River County, FL

Komatsuna Planting Calendar

Activity When Date Range
Start Indoors December 29 Dec 29 – Jan 12
Transplant Outdoors January 26 Jan 26 – Feb 9
Direct Sow January 5 Jan 5 – Jan 26
Harvest March 2 Mar 2 – Apr 6
Fall Sowing October 25 Oct 25 – Nov 8

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

328 days in Indian River County

Growing Tips for Komatsuna in Indian River County

Direct sow Komatsuna outdoors after January 26 in Indian River County when soil has warmed and frost danger has passed.

Sandy soil in Indian River 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 97°F in Indian River County, provide afternoon shade for Komatsuna and water deeply in the morning.

Your generous 329.0-day season in Indian River 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 Indian River County, FL?

Indian River County is in Zone 10a with an average last frost of January 26. Plan your Komatsuna planting based on this frost date — see the calendar above for exact timing.

What planting zone is Indian River County, FL?

Indian River County, Florida is in USDA Hardiness Zone 10a. The average last spring frost is January 26 and first fall frost is December 20.

🌱

Your Indian River County Garden Planner — Free

A 24-page printable planner built for Indian River 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 Indian River 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.