When to Plant Fennel in Arizona

Growing Fennel in Arizona: Complete Guide

Fennel (Foeniculum vulgare) is a warm-season crop that needs a head start indoors before Arizona's last frost. Depending on your zone, Arizona gardeners start seeds indoors between December 28, 2026 (Zone 10a) and March 28, 2027 (Zone 5b), then move transplants outside once their zone's last frost has passed — the zone table above has your exact dates.

Because Arizona stretches across 10 USDA hardiness zones (5b, 6a, 6b, 7a, 7b, 8a, 8b, 9a, 9b, 10a), 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 Arizona'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. In the arid Southwest, intense sun and low humidity mean irrigation is essential; mulch to prevent rapid soil moisture loss.

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 Arizona.