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When to Plant Fennel (herb) in Lincoln County, WY

Lincoln County, Wyoming Zone 5b May

May to-do list for Lincoln County, Wyoming

Your Lincoln County, Wyoming garden is entering a new phase. Here's what's on the schedule for May and why each task matters now.

Avg. last frost June 7
Avg. first frost September 13
Soil temp (4") 34°F
Watering High
Pest pressure Low
Daylight 14.4 hrs
  1. Transplant fennel (herb) outside

    Your last frost (June 7) has passed. These warm-season crops can handle outdoor soil now.

  2. Sow fennel (herb) where they'll grow

    Thin ruthlessly once seedlings are up. Crowded roots mean smaller crops from every plant.

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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.

Lincoln County, Wyoming is in USDA Zone 5b. The average last spring frost is June 7 and the first fall frost is September 13, giving you a growing season of approximately 98 days.

At an elevation of 6,850 feet, Lincoln County receives approximately 17.6 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.

Lincoln County, WY (Zone 5b) Very short season
98 days
Last Spring Frost June 7
98 growing days
First Fall Frost September 13

Lincoln County Soil Profile

Soil Type

Loam

Soil pH

6.7-8.3

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Start indoors: Apr 17 Transplant: May 15 🍅 Harvest: Jul 17 – Sep 25
Recommended (50%) ✗ May not fit
Start indoors: May 3 Transplant: May 31 🍅 Harvest: Aug 2 – Oct 11
Safe Start (90%) ✗ May not fit
Start indoors: May 17 Transplant: Jun 14 🍅 Harvest: Aug 16 – Oct 25

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 Lincoln County

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

Soil pH

Your soil pH (6.7–8.3) is more alkaline than Fennel (herb) prefers (5.5–7.0). Add sulfur or peat moss to lower pH.

Soil Texture

The loam soil in Lincoln County is excellent for Fennel (herb) — good drainage, moisture retention, and nutrient holding capacity.

Drainage

Drainage is adequate for Fennel (herb).

Organic Matter

Organic matter is moderate (2.7%). 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.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.8″/week
You supply
0.7″/week
Watering frequency 1-2 times/week
Season total 571 gal / 100 sq ft
Drought risk

Water stress score is 8/10 — 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 1.3" 0" ❄️ Dormant
Feb 1.1" 0" ❄️ Dormant
Mar 1.7" 0" ❄️ Dormant
Apr 1.6" 0" ❄️ Dormant
May 1.9" 0" ❄️ Dormant
Jun 4.3" 1.2" 3.1" 🚿 Regular watering
Jul 4.3" 1.7" 2.6" 🚿 Regular watering
Aug 4.3" 2" 2.3" 🚿 Regular watering
Sep 4.3" 1.6" 2.7" 🚿 Regular watering
Oct 1.6" 0" ❄️ Dormant
Nov 1.1" 0" ❄️ Dormant
Dec 0.9" 0" ❄️ Dormant

Water needs are for active growing months only (Jun–Sep in Lincoln County). Supplement amounts are based on average rainfall — 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" — every day above 50°F 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 ~975 GDD — county provides 1,274 GDD Excellent fit

Fennel (herb) Planting Timeline — Lincoln County, WY

Fennel (herb) Planting Calendar

Activity When Date Range
Start Indoors May 3 May 3 – May 17
Transplant Outdoors May 31 May 31 – Jun 14
Direct Sow May 24 May 24 – Jun 14
Harvest August 2 Aug 2 – Oct 11
Fall Sowing July 5 Jul 5 – Jul 19

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · 1-2 times/week

📅 Days to Maturity

60–90 days

🧪 Soil pH

Needs 5.5–7 · Your soil: too_alkaline

🗺️ USDA Zone

Zone 5b

📆 Growing Season

98 days in Lincoln County

Growing Tips for Fennel (herb) in Lincoln County

Direct sow Fennel (herb) outdoors after June 07 in Lincoln County when soil has warmed and frost danger has passed.

Your 98.0-day growing season in Lincoln County is tight for Fennel (herb) (60.0-90.0 days to maturity). Start indoors and choose early-maturing varieties.

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.

Lincoln County receives only 18" of rain annually. Fennel (herb) needs consistent moisture — 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 Lincoln County, WY?

Lincoln County is in Zone 5b with an average last frost of June 7. Plan your Fennel (herb) planting based on this frost date — see the calendar above for exact timing.

What planting zone is Lincoln County, WY?

Lincoln County, Wyoming is in USDA Hardiness Zone 5b. The average last spring frost is June 7 and first fall frost is September 13.

🌱

Your Lincoln County Garden Planner — Free

A 24-page printable planner built for Lincoln County (Zone 5b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

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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 Lincoln County, WY. Local conditions may vary. Last updated: May 2026.

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.