Fennel: Sowing, planting and harvest calendar
How do you sow Florence fennel under cover?
You can start Florence fennel under cover in late spring to get a head start, especially in a cooler region. Choose a variety suited to the sowing period and resistant to bolting, as early sowings are more vulnerable. Sow one seed per individual module or small pot of seed compost, following the depth stated on the packet. Keep the compost moist without waterlogging it and place the seedlings in good light.
Avoid sowing in a shared tray that will require separating the roots later: fennel is sensitive to root disturbance. Remove any germination cover once the seedlings emerge. Gradually acclimatise the young plants to outdoor conditions before planting them out after the risk of frost has passed. Keep each root ball intact, plant at the same depth as before and leave around 30 cm between plants for full-sized bulbs. Water regularly to limit stress.
How do you sow Florence fennel outdoors?
Sow Florence fennel directly outdoors in a warm, sunny, sheltered position with fertile, well-drained soil. In a temperate climate, June and July are often suitable; adapt the timing to your local conditions and the variety's recommended sowing period. Early sowings can bolt before forming a bulb, so spring or autumn sowing is not a general rule for every region.
Sow thinly in drills about 1–1.5 cm deep, following the seed packet's guidance, with around 30 cm between rows. Water gently and keep the soil evenly moist without waterlogging it. Gradually thin to one plant every 30 cm for full-sized bulbs, taking care not to disturb the remaining roots. Check young plants for slug and snail damage, and identify any pest or disease before choosing a suitable response; a homemade soap spray is not a treatment for every problem.
How do you plant Florence fennel?
Plant young Florence fennel plants outdoors after the risk of frost has passed, at a time suited to your climate and variety. Choose a warm, sunny, sheltered position with fertile, well-drained soil prepared with mature compost. Gradually acclimatise plants raised under cover to outdoor conditions before planting them out.
Water the root ball, then remove the plant carefully from its module or pot without breaking up the roots. Plant at the same depth as before, leaving around 30 cm between plants for full-sized bulbs. Gently firm the soil and water well. Keep the soil evenly moist without waterlogging it and remove competing weeds carefully. Protect young plants from slugs and snails; companion plants alone do not guarantee protection from pests.
Plant while the seedlings are still young to limit disturbance to their long roots. Do not force tangled roots apart. A marked cold spell after planting, like a shortage of water, can encourage flowering and prevent the expected swollen base from developing. Temporary protection can help if temperatures fall. This advice applies to Florence fennel grown for its fleshy base, rather than herb fennel grown mainly for leaves and seeds.
How to care for this plant
-
Thin seedlings
For Florence fennel, thin crowded seedlings after emergence to about 30 cm for full-sized bulbs or 10–15 cm for baby vegetables. Avoid disturbing the roots of plants you keep.
How do you harvest Florence fennel?
Harvest your Florence fennel when the swollen leaf bases form a firm, tender bulb, before it elongates and sends up a flower stem. A width of around 10–15 cm is a useful guide for full-sized bulbs, but you can pick them smaller. Harvesting time depends on the sowing date, variety and weather.
Cut just below the swollen bulb with a sharp knife. Trim off the foliage and remove only damaged outer layers; healthy young leaves can flavour dishes. If you leave the base and roots in the ground, small leafy shoots may regrow, but not another bulb. Use the harvest soon or keep it in the fridge for a few days, checking its condition. For longer storage, prepare portions for freezing using an appropriate blanching and cooling method.
Check the bases of several plants and harvest in stages according to their actual development. If a central stem starts rising, harvest promptly rather than waiting for a larger, more fibrous bulb. For a late crop, watch the forecast and cut before hard frosts.
Fennel
- Type : Vegetables
- Subtype : Root vegetables
- Botanical Family : Apiaceae (umbelliferae)
Characteristics
- Lifecycle : Annual
- Exposure : Full Sun
- Frost Hardiness : Frost Resistant
- Cultivation Difficulty : Medium
- Mature height : 60 cm
Sowing & Planting
- Greenhouse Growing : Not Required
- Sowing Depth : 1 cm
- Plant Spacing : 15 cm
- Row Spacing : 40 cm
Maintenance
- Maintenance : Moderate
- Water Requirements : Moderate
Other characteristics
- Soil Type : Humus-rich
- Soil pH Preference : Neutral
- Pest Sensitivity : Moderate
- Disease Sensitivity : Moderate
- Weed Sensitivity : Moderate
- Pollination : Insect-pollinated
- Propagation : Sowing