Also known as Florence fennel · Fennel bulb · Fennel
Choose Florence/bulb fennel, not ordinary herb fennel, if you want the grocery-store bulb. Stress and rising heat cause bolting before the base swells.
EdibleCool-season crop
Growing spaceVegetable bedClimate fitUrban core · USDA 9b–10a · Valley suburbs · USDA 9a–9b · Desert outskirts · USDA 8b–9bCrop familyApiaceae (carrot)Life cycleAnnual cropPhoenix planting windowOctober–November or February, with fall preferred for bulb quality.How to plantDirect sow or transplant very young starts without disturbing roots.Plant spacing10–12 inFrostLight frost tolerated; protect young starts during hard freezes.Time to harvestVariety-dependent; harvest swollen bases while tenderSuccessionSmall fall sowings 2–3 weeks apart.Special categoriesEDIBLETypical harvestCut tender bulbs in winter or early spring; fronds are edible.
Before you plant
These conditions determine whether it will thrive.
Cold hardinessCover while young
Established plants take light frost. Protect young starts in a hard freeze.
Heat toleranceNeeds afternoon shade
Heat and long days make it bolt before the bulb forms. Grow it through winter and harvest by March in Phoenix.
Choose Florence/bulb fennel, not ordinary herb fennel, if you want the grocery-store bulb. Stress and rising heat cause bolting before the base swells.
Best regional fit: Urban core · USDA 9b–10a, Valley suburbs · USDA 9a–9b, Desert outskirts · USDA 8b–9b.
Light
Sun exposure
Full winter sun; give leafy crops afternoon protection during warm fall and spring weather.
Water
Irrigation
Keep the vegetable root zone evenly moist with regular irrigation; adjust to rain, soil, and temperature rather than using a fixed summer schedule.
Planting & stewardship
How to help Bulb fennel thrive
1
Prepare a fertile, well-drained bed and keep seed or transplants evenly moist through establishment.
2
Thin to the final spacing; crowding reduces harvest quality.
3
Watch for aphids and caterpillars and protect sensitive growth from a hard freeze.
4
Harvest before sustained spring heat causes bolting or poor quality.
