Fennels in Perranuthnoe

Foeniculum vulgare

Fennel
Fennel · 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.

150 cm · Full Sun · Moderate Water

Add to garden

Calibrated to Perranuthnoe · last frost ≈ 26 Mar

Sow March to May, plant out April to May, harvest July to November. Frost risk November to March.
ActivityJanuaryFebruaryMarchAprilMayJuneJulyAugustSeptemberOctoberNovemberDecember
SowNoNoYesYesYesNoNoNoNoNoNoNo
Plant outNoNoNoYesYesNoNoNoNoNoNoNo
HarvestNoNoNoNoNoNoYesYesYesYesYesNo

Growing guide

Step-by-step instructions for growing Fennel

  1. 01

    Sow Seeds

    12 Mar to 10 May every 3 weeks

    Sow seeds thinly around 12th March - 10th 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.

  2. 02

    Thin Seedlings

    24 Apr to 8 May

    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 24th April to 8th May.

  3. 03

    Plant Out

    9 Apr to 26 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 9th April - 26th May.

  4. 04

    Water and Pinch Out

    2 May to 28 Nov

    Keep plants evenly moist from 2nd May to 28th November, 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.

  5. 05

    Harvest Foliage and Seed

    3 Jul to 28 Nov

    Pick young leaves from 3rd 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 3rd July to 28th November once they turn brown and dry.

Companion plants

Tap a plant to see why it works (or doesn't) with Fennel.

Plants to avoid

Why companion planting matters

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.

Suggested varieties

Popular varieties of Fennel to consider

Purpureum

A bronze-leaved fennel grown for foliage colour and ornamental value as well as flavour.

Giant Bronze

A tall, bronze selection with feathery leaves and good garden presence.

Sweet Fennel

A reliable green fennel type grown for leaves and seed in the herb garden.

Fennel guides by town

See how Fennel timing shifts in other towns with different frost dates.