When to Plant Fennel in Fremont County, WY
Your May game plan for Fremont County, Wyoming
Welcome to May in Zone 5a. These are the moves that will have the biggest impact on your growing season.
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Time to transplant fennel
Bring a watering can to the bed. Each transplant gets a drink the moment it's in the ground, not ten minutes later.
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Plant fennel from seed, right in the garden
Keep the top inch of soil moist until germination — a gentle morning watering for 5–7 days does the job.
Florence fennel is grown for its swollen bulb-like stem base, which has a mild anise flavor. It is crisp raw in salads and sweet when roasted or braised.
Fremont County, Wyoming is in USDA Zone 5a. The average last spring frost is May 15 and the first fall frost is September 21, giving you a growing season of approximately 129 days.
At an elevation of 6,059 feet, Fremont County receives approximately 14.8 inches of rainfall annually with predominantly loam soil. Summer highs average 80°F, so choose short-season varieties of Fennel to ensure they mature before fall. With low rainfall, drip irrigation is essential for growing Fennel successfully. Mulch heavily to conserve soil moisture.
Fremont County Soil Profile
Soil Type
Loam
Soil pH
6.7-7.8
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.
Soil Compatibility in Fremont County
How your county's soil matches Fennel's growing requirements.
Soil pH
Your soil pH (6.7–7.8) is more alkaline than Fennel prefers (5.5–7.0). Add sulfur or peat moss to lower pH.
Soil Texture
The loam soil in Fremont County is excellent for Fennel — good drainage, moisture retention, and nutrient holding capacity.
Drainage
Drainage is adequate for Fennel.
Organic Matter
Organic matter is moderate (2.4%). Annual compost additions will help Fennel.
How to Plant Fennel
Succession Planting Fennel
Sow every 6.9 weeks. Last sowing by Jun 23 to harvest before frost.
Plant Water Budget
Water stress score is 6/10 — consider drought-tolerant varieties and mulching
Monthly Watering Guide for Fennel
Fennel needs approximately 0.6 inches of water per week (2.6" per month). Here's how your county's rainfall compares month by month.
| Month | Fennel Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 1.1" | 0" | ❄️ Dormant |
| Feb | — | 1" | 0" | ❄️ Dormant |
| Mar | — | 1.4" | 0" | ❄️ Dormant |
| Apr | — | 1.3" | 0" | ❄️ Dormant |
| May | 2.6" | 1.8" | 0.8" | 💧 Light watering |
| Jun | 2.6" | 1.2" | 1.4" | 🚿 Regular watering |
| Jul | 2.6" | 1.2" | 1.4" | 🚿 Regular watering |
| Aug | 2.6" | 1.4" | 1.2" | 💧 Light watering |
| Sep | 2.6" | 1.3" | 1.3" | 🚿 Regular watering |
| Oct | — | 1.2" | 0" | ❄️ Dormant |
| Nov | — | 1.2" | 0" | ❄️ Dormant |
| Dec | — | 0.7" | 0" | ❄️ Dormant |
Water needs are for active growing months only (May–Sep in Fremont County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Fennel 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 Planting Timeline — Fremont County, WY
Fennel Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | March 20 | Mar 20 – Apr 3 |
| Transplant Outdoors | May 29 | May 29 – Jun 12 |
| Direct Sow | May 22 | May 22 – Jun 12 |
| Harvest | July 31 | Jul 31 – Sep 11 |
Plant 1" deep · 15" apart · Rows 24" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | Start Indoors |
| April | Start Indoors |
| May | Transplant Outdoors Direct Sow |
| June | Transplant Outdoors Direct Sow |
| July | Harvest |
| August | Harvest |
| September | Harvest |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
0.6"/week · 1-2 times/week
📅 Days to Maturity
60–90 days
🧪 Soil pH
Needs 5.5–7 · Your soil: too_alkaline
🗺️ USDA Zone
Zone 5a
📆 Growing Season
129 days in Fremont County
Growing Tips for Fennel in Fremont County
Direct sow Fennel outdoors after May 15 in Fremont County when soil has warmed and frost danger has passed.
Common pests for Fennel in this region include carrot rust fly and parsleyworm. Use row covers early in the season and inspect plants weekly.
General growing tips
Direct sow in late summer for fall harvest to reduce bolting. Hill soil around bulbs as they enlarge. Harvest when bulbs are tennis-ball sized before they elongate.
Companion Planting
Good Companions
Avoid Planting Near
Check more plant combinations with our Companion Planting Checker →
Fennel in Other Locations
Frequently Asked Questions
When should I plant Fennel in Fremont County, WY?
Fremont County is in Zone 5a with an average last frost of May 15. Plan your Fennel planting based on this frost date — see the calendar above for exact timing.
What planting zone is Fremont County, WY?
Fremont County, Wyoming is in USDA Hardiness Zone 5a. The average last spring frost is May 15 and first fall frost is September 21.
Your Fremont County Garden Planner — Free
A 24-page printable planner built for Fremont County (Zone 5a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.