Celeriac

Sun

Full sun; light afternoon shade is useful in hot climates.

Water

Keep the soil consistently moist but not waterlogged; drought produces small, tough roots.

Soil

Deep, fertile, moisture-retentive but well-drained soil, ideally with a pH of 6.0-7.5.

Height

1-2 ft (0.3-0.6 m)

Spread

1-1.5 ft (0.3-0.45 m)

Foliage

Upright clusters of dark green, divided leaves on grooved stalks, with a strong celery scent when crushed.

Growth

Slow to establish, then moderate; needs a long season to mature.

Care needed

Medium

• Low allergen
• Edible

Northern hemisphere months. In Australia, shift them by six.

Difficulty

Moderate

Toughness

Needs looking after

Pick your zone, country, light and whether you have pets.

1. Planting day

   0.5 ft (0.15 m)

2. After 1 year

   1.5 ft (0.45 m)

   full size

Full size in one season.

From a typical nursery size, at an average rate for this kind of plant. A rule of thumb, not a forecast.

Cats and dogs

Safe

Growth rate

Slow

• Work well-rotted compost into the bed before planting.
• Space plants 12-18 in (30-45 cm) apart, keeping the crown at soil level.
• Water deeply whenever the soil begins to dry; do not let developing roots suffer drought.
• Mulch around plants to conserve moisture, leaving the crown uncovered.
• Feed with a balanced vegetable fertiliser according to the label, especially on poor soil.
• Keep weeds down by hand or with shallow hoeing to avoid damaging roots.

Pruning. Remove yellowing or damaged outer leaves as needed, but retain healthy foliage to feed the developing root. Do not earth up or blanch the swollen base.

Lift the swollen bases from autumn onwards, usually about 3-5 months after transplanting, once they are roughly 3-5 in (8-13 cm) across; smaller roots are also edible. Loosen the soil with a fork, lift carefully, then trim off the leaves and fine roots. Plants tolerate light frosts, but lift before the ground freezes hard; in mild climates, leave them in the bed and harvest as needed.

Late winter

In cool climates, surface-sow seed indoors about 10-12 weeks before the expected last frost.

Early spring

Prick seedlings into individual pots and keep them warm, bright and evenly moist.

Late spring

Harden off and transplant once hard frosts have passed and prolonged cold weather is unlikely.

Summer

Water regularly, mulch and remove weeds while the swollen bases develop.

Late summer

In warm, frost-light regions, sow for a crop grown through the cooler months rather than summer heat.

Autumn

Begin harvesting roots as they reach a useful size; remove yellowing foliage.

Late autumn

In cold regions, lift remaining roots before hard freezes and store them cool, humid and frost-free.

• Plant in orderly rows in a kitchen garden, where the leafy tops give structure through summer.
• Use in raised vegetable beds with rich soil and reliable irrigation.
• Combine with lettuce and beetroot in a potager for contrasting leaf shapes and colours.
• Grow in an accessible edible bed where the exposed swollen bases make crop development easy to follow.

Garden styles it suits: Potager (kitchen garden), Edible landscape, Homestead, Cottage garden, Farmhouse and Family-friendly.

Plant it with: Lettuce, Beetroot, Leeks, Onions, Kale and Dwarf French beans.

Wildlife: If left to flower in its second year, the small white flower clusters attract hoverflies and other small beneficial insects. Crops harvested in their first year provide little floral food.

• Slugs and snails damage seedlings and young foliage: inspect after dark, remove hiding places and use locally approved controls if needed.
• Celery leaf miner causes pale or brown blotches in leaves: remove affected leaves promptly and protect young plants with insect mesh.
• Septoria leaf spot causes brown spots and declining foliage: use healthy seed, rotate crops, remove infected debris and water the soil rather than the leaves.
• Premature flowering or small, woody roots follow prolonged seedling chilling or drought: keep young plants warm and maintain even moisture after planting.

The swollen base, leaves and stalks are edible for people, but celery allergy can cause severe reactions, including anaphylaxis. Sap on the skin followed by sunlight can cause irritation or blistering in susceptible people. Celeriac is not known to be toxic to cats, dogs or horses in ordinary food amounts; large quantities may cause digestive upset.

• Celery (Apium graveolens var. dulce)

  Celery develops thick, fleshy leaf stalks rather than the large, rounded swollen base of celeriac.

• Turnip (Brassica rapa subsp. rapa)

  Turnips have broad, often rough leaves and a smoother swollen root; celeriac has divided, celery-scented leaves and a knobbly base covered with root scars.

The name celeriac derives from celery, while the botanical epithet rapaceum means turnip-like, referring to its swollen base.

Propagation. Grow from seed, surface-sown or barely covered because light aids germination. Keep at about 65-70°F (18-21°C) and consistently moist; germination commonly takes 2-3 weeks and can be uneven. Allow roughly 5-7 months from sowing to harvest, depending on variety and conditions.

Accepted botanical name

Apium graveolens dulce Apium graveolens var. rapaceum is an older name for Apium graveolens dulce.

Sources: GBIF (CC BY 4.0). The care and design notes are LandscapeGPT's own.