When to Plant Fennel (herb) in Teller County, CO
Herb fennel is grown for its aromatic leaves, stalks, and seeds rather than a bulb. It has a strong anise flavor and its flowers attract beneficial insects.
Teller County, Colorado is in USDA Zone 5a. The average last spring frost is May 11 and the first fall frost is October 6, giving you a growing season of approximately 148 days.
At an elevation of 6,538 feet, Teller County receives approximately 19.5 inches of rainfall annually with predominantly loam soil. Summer highs average 84°F, so choose short-season varieties of Fennel (herb) to ensure they mature before fall. With low rainfall, drip irrigation is essential for growing Fennel (herb) successfully. Mulch heavily to conserve soil moisture.
Teller County Soil Profile
Soil Type
Loam
Soil pH
6.4-8.1
Drainage
Well Drained
Plant Planting Risk Windows
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.
Plant Water Budget
Water stress score is 6/10 — consider drought-tolerant varieties and mulching
Fennel (herb) Planting Timeline — Teller County, CO
Fennel (herb) Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | April 6 | Apr 6 – Apr 20 |
| Transplant Outdoors | May 4 | May 4 – May 18 |
| Direct Sow | April 27 | Apr 27 – May 18 |
| Fall Sowing | July 28 | Jul 28 – Aug 11 |
| Harvest | July 6 | Jul 6 – Sep 14 |
Plant 1" deep · 15" apart · Rows 24" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | — |
| April | Start Indoors Direct Sow |
| May | Transplant Outdoors Direct Sow |
| June | — |
| July | Fall Sowing Harvest |
| August | Fall Sowing Harvest |
| September | Harvest |
| October | — |
| November | — |
| December | — |
Growing Conditions
Sun
Full Sun (6-8+ hours)
Water
Moderate — regular watering
Days to Maturity
60–90 days
Soil pH
5.5 – 7
USDA Zone
Zone 5a
Growing Season
148 days
Growing Tips for Teller County
Direct sow in spring or fall. Unlike Florence fennel, herb fennel does not form a bulb. Harvest fronds as needed and seeds when they turn brown. Self-sows readily.
Companion Planting
Good Companions
Avoid Planting Near
Level Up Your Garden
Fennel (herb) in Other Locations
Frequently Asked Questions
When should I plant Fennel (herb) in Teller County, CO?
Teller County is in Zone 5a with an average last frost of May 11. Plan your Fennel (herb) planting based on this frost date — see the calendar above for exact timing.
What planting zone is Teller County, CO?
Teller County, Colorado is in USDA Hardiness Zone 5a. The average last spring frost is May 11 and first fall frost is October 6.
Plan Your Garden with Confidence
Get our free Garden Planner — designed to help Teller County gardeners in Zone 5a organize planting dates, track what's growing, and never miss a planting window.
Get Your Free Garden Planner →Free download. Plan your entire garden season in minutes.