When to Plant Fennel in Biwabik, Minnesota (55708)

Location

Biwabik, Minnesota

ZIP Code

55708

USDA Zone

Last Frost

Wednesday, May 20, 2026

📅 Your 2026 Planting Dates

Start Seeds Indoors

Wednesday, April 22, 2026

Transplant Outdoors

Wednesday, May 6, 2026

Based on last frost Wednesday, May 20, 2026 · Zone 3b

Pro tip: Start Fennel seeds indoors 4 weeks before your last frost date, then transplant outdoors around Wednesday, May 6, 2026.

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🌿 Plant Details

Scientific Name Foeniculum vulgare

Days to Maturity 80 days

☀️ Growing Requirements

☀️

Sun

Full Sun

💧

Water

Regular

Seeds typically germinate in 7-14 days

Ready to Plant Fennel in Biwabik?

Get your seeds now so they're ready by Wednesday, April 22, 2026.

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🤝 Good Companions

Dill

🤝

Full Companion Planting Guide for Fennel

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

🛠️ Supplies You'll Need

🌱 Seed Starting Trays 🪴 Seed Starting Mix 💡 Grow Lights 🌡️ Heat Mat 🪵 Raised Garden Bed 🌍 Vegetable Garden Soil 🛠️ Hand Trowel Set 🚿 Watering Can

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🌾 Seed Saving Guide

🟢 Easy

✅ Open-pollinated — seeds grow true to parent

When to Harvest Seed

Harvest umbels when seeds turn gray-green to brown — just before they drop.

Processing

Cut seed heads into a bag, dry 1–2 weeks, thresh to separate seeds.

Seed Viability

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

Pro Tip

Fennel cross-pollinates with dill — keep at least 300 feet apart or sacrifice one crop when saving seed.

Frequently Asked Questions

When should I plant Fennel in Biwabik, Minnesota? +

In Biwabik (Zone 3b), start Fennel seeds indoors around Wednesday, April 22, 2026 and transplant outdoors around Wednesday, May 6, 2026.

What is the last frost date for Biwabik, Minnesota? +

The average last spring frost date for Biwabik, Minnesota (ZIP 55708) is around Wednesday, May 20, 2026. This is based on NOAA climate normals for USDA Zone 3b.

How long does Fennel take to grow? +

Fennel typically matures in about 80 days from transplanting. In Biwabik, that means you can expect harvest around Wednesday, May 6, 2026 plus 80 days.

Should I start Fennel indoors or direct sow in Minnesota? +

Fennel should be started indoors 4 weeks before your last frost date. In Biwabik, that means starting around Wednesday, April 22, 2026.

📚 More Fennel Planting Guides

🗺️

Fennel in Minnesota

Zone-by-zone breakdown · Full state guide

→ 🌡️

Zone 3b Fennel Guide

All cities in your zone · Avg dates

→

Other Plants for Biwabik

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Growing Fennel in Zone 3b

Fennel (Foeniculum vulgare) is a popular garden vegetable. In Biwabik, Minnesota, which is in USDA Hardiness Zone 3b, you should start seeds indoors around Wednesday, April 22, 2026.

Your average last frost date is Wednesday, May 20, 2026. Plan to transplant your Fennel seedlings outdoors around Wednesday, May 6, 2026, about -2 weeks after your last frost date.