
Foeniculum vulgare
Fennel is a hardy herb grown for its feathery foliage and aniseed-flavoured seeds, and sometimes for crisp bulbs in specialist varieties. In UK gardens it does best in full sun, in fertile, free-draining soil, and it dislikes being moved once established.
Step-by-step instructions for growing Fennel
Sow seeds thinly around 2nd April - 31st May on the surface of fine seed compost, then cover with a light dusting at most. Keep the compost just moist while they germinate, and sow a fresh batch every 21 days if you want a longer picking period.
When seedlings are large enough to handle, thin them so each plant has room to make a strong root. Keep the best seedlings and remove the rest cleanly to avoid crowding from 15th May to 29th May.
Move seedlings to their final position once the roots have filled the modules, then water in thoroughly straight away. Space them apart in full sun and free-draining soil, and use a cloche or fleece if cold weather returns around 30th April - 16th June.
Keep plants evenly moist from 23rd May to 22nd October, especially in dry spells, but do not leave the soil soggy. Pinch out the growing tips regularly so the plants stay bushy and are less likely to bolt.
Pick young leaves from 24th July and keep cutting little and often to encourage more growth. Let some plants flower if you want seed, then collect the ripe heads from 24th July to 22nd October once they turn brown and dry.
Tap a plant to see why it works (or doesn't) with Fennel.
Companion planting can deter pests, improve pollination, and make better use of space. Some plants confuse pests or attract beneficial insects; others improve soil or offer shade to neighbours that need it.
Popular varieties of Fennel to consider
A bronze-leaved fennel grown for foliage colour and ornamental value as well as flavour.
A tall, bronze selection with feathery leaves and good garden presence.
A reliable green fennel type grown for leaves and seed in the herb garden.
See how Fennel timing shifts in other towns with different frost dates.