Celery Roem van Zwijndrecht organic seeds - Apium graveolens

'Roem van Zwijndrecht' is a traditional celeriac, widely cultivated in the Netherlands, prized for its small, regular bulbs and its pronounced aroma. This variety, available here as organic seeds, produces more modest roots than giant types like the 'Giant of Prague', but with a fine, concentrated flavour, very well-suited to everyday cooking. The plant forms a leafy clump, which can be planted in the kitchen garden or in a raised bed. Its primary use remains the production of roots with white, firm flesh, ideal for winter soups, purées, and rémoulades.

Celeriac belongs to the Apiaceae family. The botanical species is Apium graveolens, whose main common names are celery, celeriac, turnip-rooted celery, knob celery, or even pot-bellied celery. It is a salt-loving plant of marshes and salty shores, found on the coasts of Europe, North Africa, and as far as Western Asia, which, through selection, gave rise to the vegetable forms of celery, leaf celery, and celeriac.
Celeriac is a biennial plant: in the first year, it forms a rosette of leaves and the tuberised root; in the second year, if not harvested, the stem elongates and bears umbels of small greenish-white, nectar-rich flowers, pollinated by insects, followed by small dry fruits (seeds) that separate into two achenes.

'Roem van Zwijndrecht' (Dutch commercial synonym Zwijndrechtsche, sometimes translated into English as 'Glory of Zwijndrecht') is classified as a heritage variety in the Netherlands. It is listed in old root vegetable catalogues before 1943 and is still distributed by several organic seed companies. It is a non-hybrid variety, with reproducible seeds, provided there is isolation from other celery types. This cultivar is distinguished by its particularly leafy habit, its good resistance to running to seed, and the rarity of 'hollow hearts' in the roots.
The plant forms a dense basal clump, with very divided, dark green foliage, and hollow, aromatic petioles. The root is round to slightly trapezoidal, covered in a beige-grey skin, with a strong beard of rootlets whose insertion reaches almost halfway up the height of the bulb. The roots remain almost entirely buried, with the top barely protruding from the soil. The average diameter of the "bulbs" reaches 8 to 10 cm. Their white to cream flesh is firm, very aromatic, with a tendency to discolour slightly when exposed to air if not treated with lemon juice.
This 'Roem van Zwijndrecht' variety shows low sensitivity to bolting and hollow hearts, but remains quite susceptible to "internal blackening" (blackening of the flesh) and to celery mosaic virus if crop rotation and feeding (particularly with boron) are not carefully managed. The foliage is destroyed by the first frosts, and the roots, although they can tolerate a little cold under mulch, should be harvested before the true winter frosts to be stored in a cellar or clamp.

In the kitchen, celeriac is cultivated for its large root. It can be eaten raw (grated, in rémoulade…) or cooked (in purée, gratin, or sautéed). Celery is rich in vitamins and mineral salts and low in calories.

In the kitchen garden, plant celeriac in a sunny or partially shaded spot. It appreciates moist, light, and rich soil. Add well-rotted compost in the preceding autumn after thoroughly loosening the soil. During cultivation, plan for the application of vegetable garden fertiliser as celery has high nutritional demands.

The harvest: harvest celeriac in autumn, before the first frosts. Lift the bulbs, let them dry out on the soil for a day, and cut the leaves above the collar as well as the rootlets.

Storage: Celeriac should be stored in a cool, humid place, protected from light, and will keep for several months.

The gardener's little tip: To limit watering, we advise you to mulch the soil with successive thin layers of grass clippings, if possible mixed with dead leaves from the end of May. This protection, which helps the soil retain moisture, also reduces weeding.