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When to Plant Mizuna in Saint Petersburg, Florida (33708)

Location

Saint Petersburg, Florida

ZIP Code

33708

USDA Zone

10b

Last Frost

Thursday, January 15, 2026

📅 Your 2026 Planting Dates

Direct Sow Outdoors

Thursday, December 18, 2025

Based on last frost Thursday, January 15, 2026 · Zone 10b

Pro tip: Sow Mizuna directly outdoors 4 weeks before your last frost date.

🌿 Plant Details

Scientific Name Brassica rapa var. nipposinica
Days to Maturity 40 days
Mature Height 8-18"
Spread 8"

☀️ Growing Requirements

☀️

Sun

Partial to Full Sun (4-6 hours)

💧

Water

Regular (1-2 inches/week)

↔️

Spacing

6" apart

🌱

Planting Depth

0.25" deep

Seeds typically germinate in 4-7 days

Ready to Plant Mizuna in Saint Petersburg?

Get your seeds now so they're ready by Thursday, December 18, 2025.

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🤝 Good Companions

CarrotOnionBeetSpinach

⚠️ Avoid Planting Near

StrawberryTomato
🤝

Full Companion Planting Guide for Mizuna

See which plants help Mizuna thrive, which to keep away, and raised bed layout tips →

🛠️ Supplies You'll Need

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🌾 Seed Saving Guide

🟢 Easy
✅ Open-pollinated — seeds grow true to parent

When to Harvest Seed

Let plants bolt fully. Harvest seed pods when tan and dry before they shatter.

Processing

Thresh dried stalks to release seeds, winnow to separate from chaff.

Seed Viability

Up to 4 years when stored cool, dark, and dry.

Pro Tip

Mizuna is a Brassica rapa and will cross with other mustard-family plants — isolate by 300 feet for purity.

🪴

Raised Bed Planting Guides

A 4×8 bed fits 4 per sq ft of Mizuna. See plant counts, spacing grids, and companion pairings for every bed size →

Frequently Asked Questions

When should I plant Mizuna in Saint Petersburg, Florida? +

In Saint Petersburg (Zone 10b), direct sow Mizuna outdoors around Thursday, December 18, 2025.

What is the last frost date for Saint Petersburg, Florida? +

The average last spring frost date for Saint Petersburg, Florida (ZIP 33708) is around Thursday, January 15, 2026. This is based on NOAA climate normals for USDA Zone 10b.

How long does Mizuna take to grow? +

Mizuna typically matures in about 40 days from direct sowing. In Saint Petersburg, that means you can expect harvest around Thursday, December 18, 2025 plus 40 days.

Should I start Mizuna indoors or direct sow in Florida? +

Mizuna does best when direct sown outdoors. In Saint Petersburg, sow directly around Thursday, December 18, 2025.

Other Plants for Saint Petersburg

Growing Mizuna in Zone 10b

Mizuna (Brassica rapa var. nipposinica) is a popular garden vegetable. In Saint Petersburg, Florida, which is in USDA Hardiness Zone 10b, you should direct sow seeds around Thursday, December 18, 2025.

Your average last frost date is Thursday, January 15, 2026. Mizuna grows well when direct sown, as it doesn't transplant well or germinates quickly outdoors.