Florence fennel

Foeniculum vulgare

Florence fennel makes a swollen bulb with an aniseed flavour at the base of its leaves. The main problem is bolting, when it flowers instead of making a bulb. To avoid it, sow in early summer rather than spring and choose a variety that resists bolting. Sow in modules, small trays of separate cells, so the roots aren't disturbed. Once the base starts to swell, pile soil up around it to keep it white and sweet.

Looking after it

Water: It needs a lot of water. Keep the soil moist all the time, because a dry spell is one of the main causes of bolting. Water generously in the morning. In summer, check a pot every day. Feeding: Fennel needs only average feeding. Dig in compost before sowing and mulch once plants are growing. It needs no other feed.

Harvest and keeping

Cut the bulb just above the soil when it is 10 to 15 cm across. Small ones you can cut from 5 cm. Don't wait until it gets longer and sends up a stem, because then it turns woody. It's best eaten fresh. In a bag in the fridge it keeps a few days.

What can go wrong

Bolting. After cold, a dry spell or disturbed roots, a flower stem shoots up and the bulb stays flat and tough. Sow later and keep watering. Use any plant that starts to bolt straight away.
Slugs and snails. They eat seedlings and young plants. Protect the plants in damp weather. Weed by hand around them, because weeds give slugs a place to hide.

Growing facts: RHS, UC ANR and seed-company sowing guides. Florence fennel care: RHS. pH: Utah State University and University of Arkansas extension.