When to Plant Thyme in Denver, Colorado (80246)

Location

Denver, Colorado

ZIP Code

80246

USDA Zone

Last Frost

Monday, April 20, 2026

📅 Your 2026 Planting Dates

Start Seeds Indoors

Monday, February 23, 2026

Transplant Outdoors

Monday, May 4, 2026

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

Pro tip: Start Thyme seeds indoors 8 weeks before your last frost date, then transplant outdoors around Monday, May 4, 2026.

🌿 Plant Details

Scientific Name Thymus vulgaris

Days to Maturity 90 days

Mature Height 6-12"

Spread 12"

Type Ground cover

Fruit Size N/A

☀️ Growing Requirements

☀️

Sun

Full Sun (6+ hours)

💧

Water

Low (drought tolerant)

↔️

Spacing

12" apart

🌱

Planting Depth

0.125" deep

Seeds typically germinate in 14-21 days

Ready to Plant Thyme in Denver?

Get your seeds now so they're ready by Monday, February 23, 2026.

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🤝 Good Companions

CabbageEggplantPotatoStrawberry

🤝

Full Companion Planting Guide for Thyme

See which plants help Thyme 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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Common Thyme Varieties

Popular cultivars to look for at your local nursery or seed supplier.

Common Thyme

species

Classic culinary thyme with small, fragrant leaves; essential in French cooking.

Lemon Thyme

cultivar

Bright citrus-scented thyme with golden-edged leaves; lovely in fish dishes and teas.

Creeping Thyme

species

Low-growing groundcover thyme with dense mats of tiny flowers; great between pavers.

French Thyme

cultivar

Broader-leaved variety with milder, sweeter flavor preferred in Provençal cooking.

🌾 Seed Saving Guide

🟡 Moderate

✅ Open-pollinated — seeds grow true to parent

When to Harvest Seed

Harvest tiny seed pods when brown and dry — just before they shatter.

Processing

Strip dried stems over a fine mesh, dry extra 2 days, store in small envelopes. Seeds are very tiny.

Seed Viability

Up to 3 years when stored cool, dark, and dry.

Pro Tip

Thyme seeds can vary in flavor intensity. Propagate from stem cuttings to preserve culinary quality.

🪴

Raised Bed Planting Guides

A 4×8 bed fits 32 plants of Thyme. See plant counts, spacing grids, and companion pairings for every bed size →

Frequently Asked Questions

When should I plant Thyme in Denver, Colorado? +

In Denver (Zone 6a), start Thyme seeds indoors around Monday, February 23, 2026 and transplant outdoors around Monday, May 4, 2026.

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

The average last spring frost date for Denver, Colorado (ZIP 80246) is around Monday, April 20, 2026. This is based on NOAA climate normals for USDA Zone 6a.

How long does Thyme take to grow? +

Thyme typically matures in about 90 days from transplanting. In Denver, that means you can expect harvest around Monday, May 4, 2026 plus 90 days.

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

Thyme should be started indoors 8 weeks before your last frost date. In Denver, that means starting around Monday, February 23, 2026.

📚 More Thyme Planting Guides

🗺️

Thyme in Colorado

Zone-by-zone breakdown · Full state guide

→ 🌡️

Zone 6a Thyme Guide

All cities in your zone · Avg dates

→

Other Plants for Denver

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Growing Thyme in Zone 6a

Thyme (Thymus vulgaris) is a popular garden vegetable. In Denver, Colorado, which is in USDA Hardiness Zone 6a, you should start seeds indoors around Monday, February 23, 2026.

Your average last frost date is Monday, April 20, 2026. Plan to transplant your Thyme seedlings outdoors around Monday, May 4, 2026, about 2 weeks after your last frost date.