Purchase fennel seeds from any nursery or home and garden center. Some suppliers offer pre-planted fennel. Follow directions on the label for your zone.
Locate a garden area with full sun exposure and good draining soil after your zone's last frost. Rich deep soil produces tender foliage.
Add a general-purpose fertilizer or mulch if needed to enrich the soil. Read directions for application.
Sow seeds 12 inches apart and cover with quarter inch of soil. For row planting space the rows 3 feet apart.
Water soil with a light spray nozzle setting until shoots appear, usually between 1 and 2 weeks, afterwards water once or twice weekly as needed.
Stake the fennel plants in windy locations when 18 inches tall, some plants reach 3 to 4 feet high.
Mulch 4 inches over the plant for winter protection with evergreen boughs, tree leaves or straw.