How to grow Florence fennel in a raised bed

Florence fennel is grown for its crisp, aniseed-flavoured bulb — lovely raw in salads or roasted until sweet. It needs cool, steady growing to bulb up well, which a raised bed makes easy to manage.

Quick facts

• Position: full sun
• Spacing: 25–30 cm apart
• Tub depth: our 35 cm depth
• Time to harvest: 12–14 weeks

When to plant: Florence fennel bulbs best in the cool — sow from late summer through autumn. Heat and stress make it bolt before it forms a bulb. Our free planting calendar shows the right months for your postcode.

Growing it in a raised bed: Sow directly, as it dislikes transplanting, and keep growth steady — any check makes it run to seed. Mound a little mix around the swelling bulb to blanch it sweeter.

Watering and feeding: Keep the mix consistently moist — irregular water is the main cause of bolting and stringy bulbs.

Common pests: keep an eye out for aphids and caterpillars. Most are easily managed — see our safe pest guide.

Common diseases: the main ones are powdery mildew. Good airflow, morning watering and steady moisture prevent most.

Companion plants: Fennel is best grown apart from other vegetables, which it can inhibit; give it its own corner. See our companion planting guide.

Harvest and storage: Harvest once the bulb is fist-sized, cutting it at the base. The ferny tops are a useful herb too. Use the bulb fresh.

More growing guides: dill, celery and horseradish.

Plan your patch: our free planting calendar shows what to plant now where you live. Ready to grow? Browse our raised garden beds or build your own with the garden bed builder.

Image: Kolforn (Kolforn), CC BY-SA 4.0, via Wikimedia Commons.