How to grow Florence fennel

Seed Sowing

Sow your seeds from May to June. They are best sown directly, as module-grown plants don’t like root disturbance and tend to bolt quickly, failing to produce bulbous bases. If you have a lot of slugs, you may need to start in modules. Sow seeds in rows around 30 cm apart; plants should be thinned to 30 cm apart. Eat the thinned plants; they are small but delicious. Best sown every two weeks for longer harvests.


Ensure your seed bed is free from weeds; sheltered sunny sites are best. Plant your seedlings carefully; they do not like root disturbance. Plant in rows around 30 cm apart, with plants 30 cm apart in the row, and water well.

Plant Care

Florence fennel can be tricky but well worth the effort. It does well in warm but damp summers, so keep it weed-free and watered during hot spells. You can mulch around the plants to retain moisture and prevent weeds.


Protect from slugs and snails, as they do like directly sown fennel. Avoid watering in the evening, as this will encourage overnight slugs and snails. Encourage predators like ground beetles, lizards, slow worms, and, if you’re lucky, hedgehogs into your growing space by creating a suitable wildlife habitat.


From seed, they take around 4 months to fully grow, but younger plants can be harvested to thin out the rows. Cut the fennel at the base with a sharp garden knife. The leaves, flowers, and seeds can also be used, so if they do bolt, they still have uses, plus the pollinators love them.

Culinary Ideas

Florence fennel is a prized vegetable. It can be cooked in slices or wedges, finely sliced raw. Cut away the fibrous base and tough outer leaves if eaten raw. It’s packed with antioxidants, vitamin C, as well as potassium. Fennel and lemon risotto, roast pork with fennel and potato bake, fennel and rocket salad, fennel and carrot slaw with walnuts, and fennel gratin are all delicious.

Seed Saving

To save seeds, let the plants flower (at least 10 together for sufficient genetic mixing). They grow up to 2 m, so they may need a cane to support them. Harvest when the seed head has turned brown. Remove seed heads and leave them in a dry, well-ventilated place to dry for at least 10 days. Rub the seeds off the dry plant and store in a cool, dry place. Stored this way, seeds can remain viable for 2-3 years.