How to prune fennel

Cut herb fennel foliage regularly throughout the growing season; remove flower heads before they open to delay bolting. For foliage, cut stems back by up to one-third, harvesting from the outer growth first. For seed, allow umbels to flower and begin to turn brown, then cut the whole seed head and dry it upside-down in a paper bag to catch seeds. Florence fennel is harvested whole at the base — no pruning needed.

Herb fennel: harvest foliage every 2–3 weeks; Florence fennel: once at harvest. Florence fennel (bulb type) needs no pruning — harvest the whole bulb. Herb fennel grown for fronds or seeds benefits from regular cutting to encourage fresh leafy growth and delay bolting. Remove flower heads promptly if you want to keep the plant producing feathery foliage; leave them if you want to harvest seeds.

For foliage, cut stems back by up to one-third, harvesting from the outer growth first. For seed, allow umbels to flower and begin to turn brown, then cut the whole seed head and dry it upside-down in a paper bag to catch seeds. Florence fennel is harvested whole at the base — no pruning needed.