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When to Plant Fennel (herb) in Baca 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.

Baca County, Colorado is in USDA Zone 6a. The average last spring frost is April 19 and the first fall frost is October 18, giving you a growing season of approximately 182 days.

At an elevation of 4,958 feet, Baca County receives approximately 12.3 inches of rainfall annually with predominantly loam soil. Summer highs average 90ยฐF, providing good warmth for Fennel (herb) during the growing season. With low rainfall, drip irrigation is essential for growing Fennel (herb) successfully. Mulch heavily to conserve soil moisture.

Baca County, CO (Zone 6a) Moderate season
182 days
Last Spring Frost April 19
182 growing days
First Fall Frost October 18

Baca County Soil Profile

Soil Type

Loam

Soil pH

6.3-7.9

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (56 days to spare)
Start indoors: Mar 10 Transplant: Apr 7 🍅 Harvest: Jun 9 – Aug 18
Recommended (50%) ✓ Fits season (56 days to spare)
Start indoors: Mar 15 Transplant: Apr 12 🍅 Harvest: Jun 14 – Aug 23
Safe Start (90%) ✓ Fits season (57 days to spare)
Start indoors: Mar 30 Transplant: Apr 27 🍅 Harvest: Jun 29 – Sep 7

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.

Soil Compatibility in Baca County

How your county's soil matches Fennel (herb)'s growing requirements.

Soil pH

Your soil pH (6.3โ€“7.9) is more alkaline than Fennel (herb) prefers (5.5โ€“7.0). Add sulfur or peat moss to lower pH.

Soil Texture

The loam soil in Baca County is excellent for Fennel (herb) โ€” good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is moderate (2.4%). Annual compost additions will help Fennel (herb).

How to Plant Fennel (herb)

1"
Planting Depth
15"
Between Plants
24"
Between Rows

Fall planting: Sow 10 weeks before your first frost date for a fall harvest.

Succession Planting Fennel (herb)

3
successive plantings in your 182-day season

Sow every 6.9 weeks. Last sowing by Jul 20 to harvest before frost.

For a dedicated fall crop, sow by Aug 09.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.3″/week
You supply
0.9″/week
Watering frequency 2-3 times/week
Season total 1,392 gal / 100 sq ft
Drought risk

Water stress score is 8/10 โ€” consider drought-tolerant varieties and mulching

Monthly Watering Guide for Fennel (herb)

Fennel (herb) needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.

Month Fennel (herb) Needs Rainfall You Supplement Action
Jan โ€” 0.8" 0" โ„๏ธ Dormant
Feb โ€” 0.7" 0" โ„๏ธ Dormant
Mar โ€” 1" 0" โ„๏ธ Dormant
Apr 4.3" 1.3" 3" ๐Ÿšฟ Regular watering
May 4.3" 1.4" 2.9" ๐Ÿšฟ Regular watering
Jun 4.3" 1" 3.3" ๐Ÿšฟ Regular watering
Jul 4.3" 1" 3.3" ๐Ÿšฟ Regular watering
Aug 4.3" 1.2" 3.1" ๐Ÿšฟ Regular watering
Sep 4.3" 1.1" 3.2" ๐Ÿšฟ Regular watering
Oct 4.3" 1.1" 3.2" ๐Ÿšฟ Regular watering
Nov โ€” 0.8" 0" โ„๏ธ Dormant
Dec โ€” 0.7" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Aprโ€“Oct in Baca County). Supplement amounts are based on average rainfall โ€” actual needs vary with temperature, soil, and mulching.

Fennel (herb) Heat Requirements (GDD)

What are Growing Degree Days (GDD)?

Growing Degree Days measure the total warmth your plants receive during the growing season. Think of it as a "heat bank" โ€” every day above 50ยฐF deposits warmth that helps your plants grow.

Each plant needs a certain amount of accumulated heat to mature. If your county provides more GDD than the plant needs, it's a great fit. If it's close, you may want to choose faster-maturing varieties or start seeds indoors to get a head start.

Fennel (herb) needs ~1,312 GDD — county provides 3,185 GDD Excellent fit

Fennel (herb) Planting Timeline โ€” Baca County, CO

Fennel (herb) Planting Calendar

Activity When Date Range
Start Indoors March 15 Mar 15 โ€“ Mar 29
Transplant Outdoors April 12 Apr 12 โ€“ Apr 26
Direct Sow April 5 Apr 5 โ€“ Apr 26
Harvest June 14 Jun 14 โ€“ Aug 23
Fall Sowing August 9 Aug 9 โ€“ Aug 23

Plant 1" deep ยท 15" apart ยท Rows 24" apart

Month-by-Month Timeline

MonthActivities
January โ€”
February โ€”
March Start Indoors
April Transplant Outdoors Direct Sow
May โ€”
June Harvest
July Harvest
August Fall Sowing Harvest
September โ€”
October โ€”
November โ€”
December โ€”

Growing Conditions

โ˜€๏ธ Sun

Full Sun (6-8+ hours)

๐Ÿ’ง Water

1"/week ยท 2-3 times/week

๐Ÿ“… Days to Maturity

60โ€“90 days

๐Ÿงช Soil pH

Needs 5.5โ€“7 ยท Your soil: too_alkaline

๐Ÿ—บ๏ธ USDA Zone

Zone 6a

๐Ÿ“† Growing Season

182 days in Baca County

Growing Tips for Fennel (herb) in Baca County

Direct sow Fennel (herb) outdoors after April 19 in Baca County when soil has warmed and frost danger has passed.

Common pests for Fennel (herb) in this region include carrot rust fly and parsleyworm. Use row covers early in the season and inspect plants weekly.

Baca County receives only 12" of rain annually. Fennel (herb) needs consistent moisture โ€” install drip irrigation or water deeply 2-3 times per week.

General growing tips

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

  • Tomatoes
  • Peppers
  • Green Beans

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Fennel (herb) in Baca County, CO?

Baca County is in Zone 6a with an average last frost of April 19. Plan your Fennel (herb) planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Baca County, CO?

Baca County, Colorado is in USDA Hardiness Zone 6a. The average last spring frost is April 19 and first fall frost is October 18.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Baca County gardeners in Zone 6a organize planting dates, track what's growing, and never miss a planting window.

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Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Baca County, CO. Local conditions may vary. Last updated: April 2026.