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Fennel growing

Photo: Unsplash

Half-hardy — needs some protection

When to plant
fennel in the UK

Sow after midsummer for best bulbs — earlier sowings often bolt. Don't transplant bare-root, it hates root disturbance. Use modules.

14wto harvest
30cmspacing
8°Cmin soil temp
half-hardyhardiness
Plan it for your plot

Work out your own dates

Starts from the recommended sow date for your area. Sowed on a different day, or planted out late? Adjust below and the harvest moves with it.

Using the UK-average last frost · 15 April · add your postcode to tune it

Sow18 March
Plant out29 Aprilpredicted
Harvest from24 June

Growing journey

Last frost
Sow indoors4w before frost
Direct sow1w after frost
Plant out2w after frost
Harvest16w after frost

14 weeks from planting out to harvest · Start indoors 6 weeks before planting out

Get fennel seeds

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What fennel need

Full sun. Well-drained, fertile soil. Regular water.

Spacing

30cm

30cm between plants

Give each plant room to spread. Overcrowding reduces yield.

the varieties

Varieties worth growing

Romanesco

common

The variety most likely to form those fat, white, anise-scented bulbs. Slower to bolt than others, which matters enormously because fennel loves to bolt. Plant it out after the longest day for the best results.

in the kitchen

Shaved fennel salad with orange

Mandoline the bulb paper-thin, toss with orange segments, black olives, a splash of olive oil, and a scatter of fronds. Sicilian sunshine in a bowl. The anise softens against the citrus.

Finale

uncommon

Bolt-resistant and quick to bulb, which is exactly what you want from fennel. The bulbs are round, white, and have that clean aniseed flavour that works raw or cooked. A modern variety that solves fennel's biggest problem.

in the kitchen

Braised fennel with parmesan

Quarter the bulbs, braise in white wine and stock until meltingly tender, scatter with parmesan and breadcrumbs, and grill until golden. The anise mellows into something sweet and gentle.

Grown for its feathery, bronze-purple foliage rather than a bulb — because it doesn't form one. Tall, architectural, and the fronds taste wonderfully of aniseed. A herb disguised as a garden ornamental. Bees and hoverflies go mad for the flowers.

in the kitchen

Fennel-frond fish

Stuff a whole sea bass with bronze fennel fronds, lemon slices, and garlic. Grill or bake until the skin crisps. The anise-scented steam perfumes the fish from the inside out.

Zefa Fino

common

Swiss-bred for bolt resistance and reliable bulb formation. Round, white bulbs with a clean anise flavour. If you've tried growing fennel before and it bolted before bulbing, this is the one to try next. It actually wants to form a bulb.

in the kitchen

Fennel, blood orange, and olive salad

Shave the bulb paper-thin, arrange with blood orange segments and black olives. Dress with olive oil and a pinch of salt. A Sicilian winter salad that brightens everything around it.

Keep apart from

  • Tomatoes
  • Carrots
Full companion planting guide & chart →

When to sow fennel

Sow indoorsMarchApril
Direct sowAprilMay
Plant outAprilMay

Based on UK average frost date. Enter your postcode for exact dates, or find your city.

Seeds

Where to buy fennel seeds

Links may be affiliate links. We may earn a small commission at no extra cost to you.

Get your exact dates

Enter your postcode for personalised planting dates for fennel.

Keep exploring

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Fold outer leaves over the curd to keep it white. Cauliflower leaves are delicio

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Pinch out side shoots on cordon types. Feed weekly with tomato feed once the fir

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Need heat to germinate — use a propagator or the warmest windowsill you've got.

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Plant bare-root canes in winter for the cheapest option. Summer varieties fruit

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