Celeriac, celery branch: sow, plant, grow, harvest

Description and botany

Celery is a descendant of marsh parsley (or wild celery), a plant native to the Mediterranean that grows in wet places. Wild celery has a bitter taste and was considered a medicinal plant rather than a vegetable until celery selections were made in the 16th century.

Celery has symbolic importance in history: in 628 BC Greeks founded the celery capital, Selinunt (Selinunte) in Sicily. Their coin (drachma) bore an image of the celery leaf. In the Middle Ages, celery appears in herbals of simples, then used as a medicinal plant. The first cultivated form of celery is thought to be cutting celery. Stalk celery was selected in Italy in the 16th century. In France, celery is first cited as a vegetable in 1562. Celeriac is mentioned in the 18th century in the Garden Kalendar of the Reverend Gilbert White.

Etymologically, “céleri” comes from “seleri”, an Italian dialect word derived from Latin selinon and referring to the plant; it also means “plant of the moon”.

Celery belongs to family Apiaceae (formerly Umbelliferae), like the carrot, the parsnip, the fennel, and many aromatic plants such as dill, coriander, parsley, etc. It is a biennial in temperate conditions, but can be perennial in some tropical conditions, in which case it does not flower. Indeed, celery must undergo vernalisation (a cold period) between the first and second year to flower.

In the garden, three species are cultivated :

• stalk celery or celery with ribs, Apium graveolens var. dulce
• celeriac, Apium graveolens var. rapaceum
• cutting celery, Apium graveolens var. secalinum

Celery can reach up to 1.20 m in height at flowering in the second year. Celery root is always slightly tuberised; celeriac has been selected for this trait and its root can weigh up to 1 kg. Leaves are glossy dark green, borne on long petioles shaped like a gutter and very fleshy in the case of stalk celery.

In the second year, celery produces a flowering stem in summer bearing an inflorescence that is an umbel composed of many small white flowers, opening from the periphery towards the centre of the umbel. Each flower is hermaphrodite, bearing both male organs (stamens, pollen) and female organs (pistil, ovary). A flower thus has 5 stamens and 2 styles, which lead to two chambers composing the ovary. One chamber contains one ovule, so each flower can produce two seeds. This seed is an achene, grouped in pairs (diachene), which separate at maturity.

Pollination is mainly carried out by insects. They are attracted by the strong fragrance emitted by the flowers and their plentiful nectar, so celery is an entomophilous plant. It is also allogamous and promotes cross fertilization. We have seen that the umbel ripens from the outside inwards, but the flower itself is protandrous, meaning stamens mature before the pistil. It takes 8 days between pollen release and stigma maturity ready to receive pollen from another flower.

Botanical plate of celery – Greek drachma showing celery – Leaf – Celeriac – Rib or petiole – Inflorescence

Celery varieties

Branch celery and cutting celery varieties

Celeriac varieties

Celery Géant Doré Amélioré

Giant Golden Improved celery is a variety that produces wide, fleshy petioles with a tender, non-stringy texture, yellow in colour and foliage green with a golden tinge. This variety is well suited to preserving.

• Flowering time August to October
• Height at maturity 70 cm

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D'Elne Celery - Apium graveolens

Vigorous, light-green and very aromatic. Midribs are broad and fleshy, gutter-shaped.

• Flowering time August to October
• Height at maturity 50 cm

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Martine Celery - Apium graveolens

Martine celery is a variety distinguished from others by the colour of its midribs — red! These are also broad, fleshy and of good flavour. Its pale green foliage with golden highlights is compact and vigorous.

• Flowering time August to October
• Height at maturity 50 cm

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Full Giant Red Celery - Apium graveolens

Full Red Giant celery is a rather old variety… It was already cultivated in 1835 under the name 'Brydon’s Prize Red'. It is more flavoursome than green midrib celeries. Its midribs are dark red, broad and thick, fleshy and have a fairly firm core.

• Flowering time August to October
• Height at maturity 50 cm

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Celery Tall Utah - Ferme de Sainte Marthe Seeds

Tall Utah celery is a hardy variety with compact, vigorous light-green foliage. It has green midribs (petioles) that are wide, fleshy, gutter-shaped, not very stringy, crisp and aromatic.

• Flowering time August to October
• Height at maturity 50 cm

See the product sheet

Leaf Celery - Ferme de Sainte Marthe Seeds

Cutting celery produces fine, hollow, short midribs with pleasant flavour and vigorous foliage. Plant reaches 30 cm in height, with good cold tolerance and very aromatic.

• Flowering time August to October
• Height at maturity 30 cm

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Westlandse dark green cutting Celery - Apium graveolens

Westlandse dark-green cutting celery is a hardy variety that tolerates frost and is very aromatic. It develops vigorous foliage with fine, hollow, short midribs of pleasant flavour.

• Flowering time August to October
• Height at maturity 30 cm

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Prague Giant Celeriac - Apium graveolens

Giant Prague celeriac is an old early variety, keeps well and is not very susceptible to rust. Its fleshy root is white, regular in shape, with a very fine flavour and not prone to hollowing.

• Flowering time August to October
• Height at maturity 50 cm

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Celeriac Monarch

Monarch celeriac is a late, robust variety, resistant to bolting, keeps well and is not very susceptible to rust. Its white flesh has a fine flavour and is not prone to hollowing. It is an improvement of the Giant Prague variety.

• Flowering time August to October
• Height at maturity 50 cm

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Celeriac Ibis - Vilmorin Seeds

Ibis celeriac is a fast-growing variety that produces round, smooth knobs with white flesh and good eating quality. It stores particularly well after harvest. It is a variety bred by Vilmorin.

• Flowering time August
• Height at maturity 60 cm

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Celeriac Goliath

Goliath celeriac is a robust variety resistant to septoria and to bolting, keeps well. It produces a large, fleshy, regular root with a fine flavour and is not prone to hollowing.

• Flowering time August to October
• Height at maturity 50 cm

See the product sheet

 

Sowing and pricking out celery

When to sow celery?

Sowing celery is a somewhat delicate task: germination is slow and requires warmth and humidity. Sow in March–April, in warmth at home or under a heated shelter, or from mid-April to late May in an in-ground nursery, possibly under a cold frame.

How to sow celery?

Sowing celeriac and celery is done like this in a seed tray (or seedling flat):

1. Fill a seed tray three-quarters full with seed compost, firm down with a tamper.
2. Sow celery seed thinly.
3. Cover with very little sieved seed compost then firm down using a small tamper.
4. Sprinkle with a little powdered charcoal or cinnamon (to prevent risk of damping-off)
5. Spray surface with a fine mist of water then maintain constant moisture (but not excessive) until germination.

Soil or compost must be kept moist at all times; you can cover the sowings until emergence with several layers of wet newspaper. Growth is very slow at the start. Temperature must be above 15°C. Germination occurs on average in 12 to 15 days.

Pricking out celery

The aim of this pricking out is to obtain strong, stocky young plants before final planting in the vegetable patch. I recommend waiting until the four true leaf stage, around late April for first March sowings. Prick out into small buckets at a rate of one young plant per bucket.

1. Fill your buckets with potting compost and make a hole in each using a dibber (or, if unavailable, a pencil).
2. Lift the best celery young plants using a dibber or a small spoon.
3. “Dress” the young plants by trimming a few centimetres off the roots
4. Place the roots into the hole, ensuring they are not turned back on themselves
5. Firm with fingers to bring compost back over the roots
6. Water gently

Keep young plants protected from frost (indoors, conservatory, cold frame, under cloches) but put them outside during the day to harden off gradually.

Photos of pricking out celery (A. Gourmelen). Wait until young plants are sufficiently developed before starting individual pricking out into buckets.

Planting celery

From mid-May to late June, once all risk of frost has passed, young plants are planted out in the vegetable plot in their final positions. They are planted in warmed soil that has been well prepared: weeded, loosened then levelled. Unlike other vegetables, the collar of celery must not be buried.

Planting distances to observe are 35 cm in all directions (between the ranks and between each young plant on the rank).

Cultivation, care and companion planting

Celery prefers fresh to even moist, deep and light soils. It requires well-manured soil, previously enriched with a supply of mature compost or manure at a rate of 3 to 4 kg per m². It also needs potash, for example in the form of wood ash. It grows in sun or partial shade.

Routine maintenance of celery consists of regular weeding and hoeing. It requires frequent, generous watering: soil must remain moist, any water stress potentially triggering bolting. These tasks can be spaced out or greatly reduced if you mulch the soil with thin successive layers of previously dried grass clippings.

During cultivation of celeriac, it is recommended to remove aerial rootlets once the bulb has formed. The midribs of stalk celery sometimes benefit from being blanched before harvest: to do this, 15 days to 3 weeks before harvest, deprive the midribs of light by wrapping them in cardboard fixed with string.

In companion planting, celery pairs favourably with leek, chard, squashes and fennel. Avoid planting near parsnips, carrots and maize. Biodynamic practitioner Volkmar Lust advises pairing it with cauliflower; the latter would protect celery from septoria and the celery fly, while celery would in turn repel the cabbage white butterfly.

Diseases and pests

Celery is relatively resistant to diseases and pests.

The main disease is septoria: attacks by this fungus cause brown spots to appear on leaves that eventually yellow and dry out. As a preventive measure, spray a Bordeaux mixture solution, or, more environmentally and soil-friendly, a horsetail decoction.

The most common pest is the carrot fly, Psila rosae. This parasitic insect, present in gardens from April to early November, affects growth of attacked plants. To deter it, lay a mulch made from debris of repellent plants (lavender, tansy).

Also note attacks by the celery fly, Philophylla heraclei. This fly appears in May and lays its eggs on celery leaves; they can descend into the petiole. The larvae create collective mines that produce large white patches on the leaves; these are shiny through translucence, then take on a dried, scorched appearance. Damage is proportional to degree of fly attack, but it reduces yield. Remove affected leaves and, as with the carrot fly, apply a mulch made from debris of repellent plants.

→Find out more in Diseases and pests of celery: identification and solutions.

Harvesting and storing

Cultivation of celery takes 6 to 7 months between sowing and harvest, which starts in August and continues until December.

Midrib celery is harvested whole or by cutting branches as required.

Cutting celery is preferably harvested leaf by leaf.

Celeriacs are pulled up using a fork and spade. Optionally leave the bulbs to dry for a whole day on dry soil, then cut the foliage at collar level and trim rootlets before storing in cellar or silo.

Leaves of stalk celery and cutting celery are best consumed fresh to fully enjoy their aroma. However, they can be dried and used as an aromatic plant or frozen. Celeriacs should be stored in a cool, humid place away from light and will then keep for several months.

Uses and nutritional value

Celery leaves are used as a condiment in soups, stews and to flavour certain sauces and stuffings; they complete bouquet garni. Raw midribs, tender, finely sliced, can be part of mixed salads or cut into sections and eaten raw for a crunchy bite. It also blends well into smoothies with some carrots and tomatoes.

Celeriac is, of course, eaten raw in remoulade with mustard mayonnaise, also in salads. Cooked, it is prepared with tomato sauce, sautéed, au gratin, mashed, in fritters or in soups. As for spices, it pairs well with nutmeg and cinnamon.

Celeries have many virtues: antirheumatic, appetising, digestive and remineralising. Celery-branch, raw or cooked, is a good source of vitamin B9 and vitamin C, as well as potassium and calcium. It also contains copper and manganese. Celeriac, for its part, is rich in vitamin B9, three times as much as celery-branch. It is a good source of vitamin B6. In terms of minerals and trace elements, it is a source of selenium and potassium. Only one small drawback: both celeries contain a non-negligible amount of sodium (less than in cured meats, rest assured), but this should be taken into account in cases of hypertension and other salt-related health issues.