Florence fennel Growing Guide
Florence fennel is an attractive plant that forms a white ‘bulb’ at ground level made up of the overlapping, swollen bases of the leaf stalks. This has a sweet, mild aniseed flavour. It’s also known as bulb fennel, although botanically it’s not a true bulb. Florence fennel (Foeniculum vulgare var. azoricum) is very closely related to the herb fennel (F. vulgare), but forms a smaller plant, ready to harvest in just a few months. It can be tricky to grow as it bolts (starts flowering) easily, which means the bulb either doesn’t form or turns woody and inedible. It fares best in warm, damp summers. It is a handsome, upright plant with feathery foliage, taking up little ground space, making it ideal for small gardens and containers. Florence fennel can be eaten raw, sliced or grated into salads, or cooked in various dishes such as steamed, grilled, roasted, or braised. Its sweet, mildly aniseed flavour goes particularly well with fish. The chopped young leaves can also be used to flavour salads and other dishes.
This guidance applies to the crop in general. Individual varieties and local conditions can differ.
Planting information
Sow seeds either direct outdoors or singly into modules indoors. Early sowings are prone to bolting, so choose bolt-resistant varieties or wait until early summer for outdoor sowing (June or July). For indoor sowing, start in a greenhouse or on a warm windowsill from late spring; use modular trays and sow one seed per module to minimize root disturbance during transplanting. Keep seedlings in good light and water regularly. For outdoor sowing, prepare the ground, make a shallow drill about 2cm deep, water along the base, and sow seeds thinly. Space neighbouring rows 30cm apart. Gradually thin out young seedlings to 30cm apart, taking care not to disturb roots. For mini veg, space plants 10-15cm apart. Protect young plants from slugs and snails. For containers, sow into large containers filled with moist peat-free multi-purpose compost; grow up to three mature plants in a 40cm wide container or space 10-15cm apart for baby veg. If grown indoors or bought as plug plants, harden them off first to acclimatise them to outdoor conditions, then plant out from early May onwards, after the last frost. Plant into prepared ground or large containers of peat-free multi-purpose compost. Do not disturb the roots and position plants at the same depth as previously growing. Space them 30cm apart for mature bulbs, or 10-15cm for harvesting as baby veg. Water them in well and protect young plants from slugs and snails.
Harvesting information
Florence fennel is ready to harvest in late summer and autumn, depending on sowing time. It is usually harvested when the bulb is 10-15cm across, but can be harvested at any size, from just 5cm upwards. Harvest before the bulb starts to elongate and send up a flower stem, at which point it becomes woody and inedible. To harvest, either dig up the whole plant or cut just below the swollen bulb with a sharp knife, leaving the base and roots in the ground. Leaving the base may result in small leafy shoots that can be used in salads, but another bulb will not form.