When to plant Fennel in Bristol

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

Calibrated to Bristol · last frost ≈ 19 Apr

Sow outdoors April to May, plant out May to June, harvest June to November. Frost risk November to April.
ActivityJanuaryFebruaryMarchAprilMayJuneJulyAugustSeptemberOctoberNovemberDecember
Sow outdoorsNoNoNoYesYesNoNoNoNoNoNoNo
Plant outNoNoNoNoYesYesNoNoNoNoNoNo
HarvestNoNoNoNoNoYesYesYesYesYesYesNo

Growing guide

What to do through the growing season

  1. 01

    Sow Seeds

    5 Apr to 3 May Optional · repeat every 3 weeks

    Sow seeds thinly around 5th April - 3rd May on a fine, raked seedbed, then cover with only a light dusting of soil. Keep the soil just moist during germination. Sow a fresh batch every 21 days for a longer picking period.

  2. 02

    Thin Seedlings

    19 Apr to 31 May Dates as each sowing reaches this stage

    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 19th April to 31st May.

  3. 03

    Thin to Final Spacing

    3 May to 19 Jun

    Direct-sown fennel needs no transplanting. Once the seedlings are established, thin them to apart in full sun and free-draining soil, and use a cloche or fleece if cold weather returns around 3rd May - 19th June.

  4. 04

    Water and Pinch Out

    3 May to 2 Nov Dates as each sowing reaches this stage

    Keep plants evenly moist from 3rd May to 2nd 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

    28 Jun to 2 Nov Dates as each sowing reaches this stage

    Pick young leaves from 28th June and keep cutting little and often to encourage fresh growth. Leave some plants to flower for seed, then collect ripe heads through 2nd November once they turn brown and dry.

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.