When to Plant Fennel in Colorado Springs, Colorado (80939)

Location

Colorado Springs, Colorado

ZIP Code

80939

USDA Zone

Last Frost

Monday, April 20, 2026

📅 Your 2026 Planting Dates

Start Seeds Indoors

Monday, March 23, 2026

Transplant Outdoors

Monday, April 6, 2026

Based on last frost Monday, April 20, 2026 · Zone 6a

Pro tip: Start Fennel seeds indoors 4 weeks before your last frost date, then transplant outdoors around Monday, April 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 Colorado Springs?

Get your seeds now so they're ready by Monday, March 23, 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 Colorado Springs, Colorado? +

In Colorado Springs (Zone 6a), start Fennel seeds indoors around Monday, March 23, 2026 and transplant outdoors around Monday, April 6, 2026.

What is the last frost date for Colorado Springs, Colorado? +

The average last spring frost date for Colorado Springs, Colorado (ZIP 80939) is around Monday, April 20, 2026. This is based on NOAA climate normals for USDA Zone 6a.

How long does Fennel take to grow? +

Fennel typically matures in about 80 days from transplanting. In Colorado Springs, that means you can expect harvest around Monday, April 6, 2026 plus 80 days.

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

Fennel should be started indoors 4 weeks before your last frost date. In Colorado Springs, that means starting around Monday, March 23, 2026.

📚 More Fennel Planting Guides

🗺️

Fennel in Colorado

Zone-by-zone breakdown · Full state guide

→ 🌡️

Zone 6a Fennel Guide

All cities in your zone · Avg dates

→

Other Plants for Colorado Springs

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Growing Fennel in Zone 6a

Fennel (Foeniculum vulgare) is a popular garden vegetable. In Colorado Springs, Colorado, which is in USDA Hardiness Zone 6a, you should start seeds indoors around Monday, March 23, 2026.

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