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When to Plant Fennel in Wasatch County, UT

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.

Wasatch County, Utah is in USDA Zone 5a. The average last spring frost is May 19 and the first fall frost is September 26, giving you a growing season of approximately 130 days.

At an elevation of 8,190 feet, Wasatch County receives approximately 16.6 inches of rainfall annually with predominantly loam soil. Summer highs average 86ยฐF, providing good warmth for Fennel during the growing season. With low rainfall, drip irrigation is essential for growing Fennel successfully. Mulch heavily to conserve soil moisture.

Wasatch County, UT (Zone 5a) Short season
130 days
Last Spring Frost May 19
130 growing days
First Fall Frost September 26

Wasatch County Soil Profile

Soil Type

Loam

Soil pH

6.6-7.6

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (20 days to spare)
Start indoors: Mar 9 Transplant: May 18 🍅 Harvest: Jul 20 – Aug 31
Recommended (50%) ✓ Fits season (11 days to spare)
Start indoors: Mar 24 Transplant: Jun 2 🍅 Harvest: Aug 4 – Sep 15
Safe Start (90%) ✓ Fits season (2 days to spare)
Start indoors: Apr 24 Transplant: Jul 3 🍅 Harvest: Sep 4 – Oct 16

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 Wasatch County

How your county's soil matches Fennel's growing requirements.

Soil pH

Your soil pH (6.6โ€“7.6) is more alkaline than Fennel prefers (5.5โ€“7.0). Add sulfur or peat moss to lower pH.

Soil Texture

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

Organic Matter

Organic matter is moderate (2.9%). Annual compost additions will help Fennel.

How to Plant Fennel

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

Succession Planting Fennel

2
successive plantings in your 130-day season

Sow every 6.9 weeks. Last sowing by Jun 28 to harvest before frost.

Plant Water Budget

Plant needs
0.6″/week
Rainfall provides
0.5″/week
You supply
0.1″/week
Watering frequency Only during dry spells
Season total 88 gal / 100 sq ft
Drought risk

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

Fennel needs ~1,088 GDD — county provides 1,885 GDD Excellent fit

Fennel Planting Timeline โ€” Wasatch County, UT

Fennel Planting Calendar

Activity When Date Range
Start Indoors March 24 Mar 24 โ€“ Apr 7
Transplant Outdoors June 2 Jun 2 โ€“ Jun 16
Direct Sow May 26 May 26 โ€“ Jun 16
Harvest August 4 Aug 4 โ€“ Sep 15

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

Month-by-Month Timeline

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

Growing Conditions

โ˜€๏ธ Sun

Full Sun (6-8+ hours)

๐Ÿ’ง Water

0.6"/week ยท Only during dry spells

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 5a

๐Ÿ“† Growing Season

130 days in Wasatch County

Growing Tips for Fennel in Wasatch County

Direct sow Fennel outdoors after May 19 in Wasatch 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

  • Tomatoes
  • Peppers
  • Beans

Level Up Your Garden

Frequently Asked Questions

When should I plant Fennel in Wasatch County, UT?

Wasatch County is in Zone 5a with an average last frost of May 19. Plan your Fennel planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Wasatch County, UT?

Wasatch County, Utah is in USDA Hardiness Zone 5a. The average last spring frost is May 19 and first fall frost is September 26.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Wasatch 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.

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