When to Plant Fennel in Utah
Start Seeds Indoors
Saturday, March 28, 2026
Transplant outdoors: Saturday, April 11, 2026
State
Utah
USDA Zones
4a, 5a, 5b, 6a, 6b, 7a, 7b, 8a, 8b
Avg Last Frost
Saturday, April 25, 2026
Cities Covered
250
Utah Planting Schedule by Zone
Utah spans 9 zones — find yours below for the most accurate dates.
| Zone | Last Frost | Start Indoors | Transplant |
|---|---|---|---|
| 4a | Friday, May 15, 2026 | Friday, April 17, 2026 | Friday, May 1, 2026 |
| 5a | Sunday, May 10, 2026 | Sunday, April 12, 2026 | Sunday, April 26, 2026 |
| 5b | Saturday, April 25, 2026 | Saturday, March 28, 2026 | Saturday, April 11, 2026 |
| 6a | Monday, April 20, 2026 | Monday, March 23, 2026 | Monday, April 6, 2026 |
| 6b | Wednesday, April 15, 2026 | Wednesday, March 18, 2026 | Wednesday, April 1, 2026 |
| 7a | Friday, April 10, 2026 | Friday, March 13, 2026 | Friday, March 27, 2026 |
| 7b | Sunday, April 5, 2026 | Sunday, March 8, 2026 | Sunday, March 22, 2026 |
| 8a | Friday, March 20, 2026 | Friday, February 20, 2026 | Friday, March 6, 2026 |
| 8b | Sunday, March 15, 2026 | Sunday, February 15, 2026 | Sunday, March 1, 2026 |
Dates based on average last frost. Check your local forecast before planting.
🌿 About Fennel
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Growing Fennel in Utah: Complete Guide
Fennel (Foeniculum vulgare) is a warm-season crop that needs a head start indoors before Utah's last frost. Most Utah gardeners begin seeds indoors around Saturday, March 28, 2026 and move transplants outside around Saturday, April 11, 2026, after the risk of frost has passed.
Because Utah stretches across 9 USDA hardiness zones (4a, 5a, 5b, 6a, 6b, 7a, 7b, 8a, 8b), planting windows can shift by as much as six to eight weeks from one end of the state to the other. Gardeners in the warmer southern zones can start earlier, while those in cooler northern zones should wait until the zone table above shows their last frost has passed.
With 80 days to maturity, Fennel needs the indoor head start that Utah's growing season requires. Starting indoors ensures you have strong transplants ready the moment outdoor conditions are right.
Fennel requires full sun and regular moisture. Most of Utah receives adequate sunlight during the growing season, though gardeners in humid eastern regions should watch for fungal issues and ensure good air circulation.
For the most precise planting dates tailored to your exact location, enter your ZIP code on our planting calendar or use the zone table above to find the schedule for your area of Utah.
Frequently Asked Questions
When should I plant Fennel in Utah?
In Utah, start Fennel seeds indoors around Saturday, March 28, 2026 and transplant outdoors around Saturday, April 11, 2026 after your last frost. Utah spans zones 4a–8b, so dates shift by 1–4 weeks depending on where you live.
What is the last frost date in Utah?
Utah spans 9 USDA zones (4a, 5a, 5b, 6a, 6b, 7a, 7b, 8a, 8b), so last frost dates vary by region. Randolph (4a) sees frost until around Friday, May 15, 2026, while Hurricane, Ivins, Leeds (8b) is frost-free much earlier.
How long does Fennel take to grow in Utah?
Fennel takes about 80 days from transplant (or direct sow) to harvest. Starting seeds indoors in Utah gives you a head start so plants are ready to go out after the last frost.
What USDA zones does Utah cover for Fennel?
Utah includes zones 4a, 5a, 5b, 6a, 6b, 7a, 7b, 8a, 8b. Fennel grows well across all of these zones with adjusted timing — use the zone table above to find the right dates for your part of the state.
Find Precise Dates for Your City
Select a city for exact planting dates based on local frost records.