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When to Plant Mizuna in Palm Beach County, FL

Palm Beach County, Florida Zone 10b May

Your May planting checklist for Palm Beach County, Florida

If you only do a handful of things in the garden this May, make it these. They're sequenced around your zone's frost timing.

Avg. last frost February 17
Soil temp (4") 81°F
Watering Moderate
Pest pressure High
Daylight 13.3 hrs

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Mizuna is a mild-flavored Japanese mustard green with feathery, deeply serrated leaves. It is fast-growing and makes an excellent addition to salads and stir-fries.

Palm Beach County, Florida is in USDA Zone 10b. The average last spring frost is February 17 and the first fall frost is April 15, giving you a growing season of approximately 57 days.

At an elevation of 355 feet, Palm Beach County receives approximately 50 inches of rainfall annually with predominantly sand soil. Summer highs average 93°F, providing good warmth for Mizuna during the growing season. Sandy soil warms quickly in spring — great for early planting — but Mizuna will need more frequent watering and organic matter to retain nutrients.

Palm Beach County, FL (Zone 10b) Very short season
57 days
Last Spring Frost February 17
57 growing days
First Fall Frost April 15

Palm Beach County Soil Profile

Soil Type

Sand

Soil pH

5.1-5.9

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (184 days to spare)
Start indoors: Jan 13 Transplant: Feb 10 🍅 Harvest: Mar 17 – Apr 14
Recommended (50%) ✓ Fits season (177 days to spare)
Start indoors: Jan 20 Transplant: Feb 17 🍅 Harvest: Mar 24 – Apr 21
Safe Start (90%) ✓ Fits season (170 days to spare)
Start indoors: Jan 27 Transplant: Feb 24 🍅 Harvest: Mar 31 – Apr 28

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 Palm Beach County

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

Soil pH

Your soil pH (5.1–5.9) is more acidic than Mizuna prefers (6.0–7.5). Add garden lime to raise pH.

Soil Texture

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

Drainage

Drainage is adequate for Mizuna.

Organic Matter

Organic matter is low (1.3%). Add 2-3 inches of compost before planting Mizuna.

How to Plant Mizuna

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

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

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.6″/week
You supply
0.7″/week
Watering frequency 2-3 times/week
Season total 2,354 gal / 100 sq ft

Monthly Watering Guide for Mizuna

Mizuna needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.

Month Mizuna Needs Rainfall You Supplement Action
Jan 2.4" 0" ❄️ Dormant
Feb 4.3" 2.3" 2" 💧 Light watering
Mar 4.3" 3.2" 1.1" 💧 Light watering
Apr 4.3" 2.4" 1.9" 💧 Light watering
May 4.3" 3.3" 1" 💧 Light watering
Jun 4.3" 6.2" 0" ✅ Rainfall sufficient
Jul 4.3" 7.3" 0" ✅ Rainfall sufficient
Aug 4.3" 7.4" 0" ✅ Rainfall sufficient
Sep 4.3" 7" 0" ✅ Rainfall sufficient
Oct 4.3" 4.2" 0.1" 💧 Light watering
Nov 2" 0" ❄️ Dormant
Dec 2.2" 0" ❄️ Dormant

Water needs are for active growing months only (Feb–Oct in Palm Beach County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.

Mizuna 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.

Mizuna needs ~741 GDD — county provides 7,208 GDD Excellent fit

Mizuna Planting Timeline — Palm Beach County, FL

Mizuna Planting Calendar

Activity When Date Range
Start Indoors January 20 Jan 20 – Feb 3
Transplant Outdoors February 17 Feb 17 – Mar 3
Direct Sow January 27 Jan 27 – Feb 17
Harvest March 24 Mar 24 – Apr 21
Fall Sowing February 18 Feb 18 – Mar 4

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 Fall Sowing
March Transplant Outdoors Fall Sowing Harvest
April Harvest
May
June
July
August
September
October
November
December

Growing Conditions

☀️ Sun

Partial Shade (3-6 hours)

💧 Water

1"/week · 2-3 times/week

📅 Days to Maturity

30–45 days

🧪 Soil pH

Needs 6–7.5 · Your soil: too_acidic

🗺️ USDA Zone

Zone 10b

📆 Growing Season

57 days in Palm Beach County

Growing Tips for Mizuna in Palm Beach County

Direct sow Mizuna outdoors after February 17 in Palm Beach County when soil has warmed and frost danger has passed.

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

Your generous 365.0-day season in Palm Beach County allows multiple plantings of Mizuna. Sow every 15.0 days for continuous harvest.

Common pests for Mizuna 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. Harvest outer leaves as needed for a cut-and-come-again approach. Mizuna is one of the most cold-tolerant Asian greens.

Companion Planting

Good Companions

Avoid Planting Near

  • Strawberries

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Mizuna in Palm Beach County, FL?

Palm Beach County is in Zone 10b with an average last frost of February 17. Plan your Mizuna planting based on this frost date — see the calendar above for exact timing.

What planting zone is Palm Beach County, FL?

Palm Beach County, Florida is in USDA Hardiness Zone 10b. The average last spring frost is February 17 and first fall frost is .

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Your Palm Beach County Garden Planner — Free

A 24-page printable planner built for Palm Beach County (Zone 10b). 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 Palm Beach 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.