Celery (Apium graveolens var. dulce) & Celeriac (A. graveolens var. rapaceum)

The Latin names for the different types of celery are revealing. In both cases, graveolens means “strong smelling” or “heavily scented.” Dulce implies sweetness, while rapaceum means “turnip-like.” Few vegetables boast such accurately descriptive names.

Celery leaves and flowers were among the plants discovered in garlands around the neck of Tutankhamun’s mummy, and he was entombed in 1324 BC. Homer mentions celery in his Iliad and Odyssey, so cultivation began early and it is still popular around the world.

About Celery and How to Make Mirepoix
Celery, along with carrots and onions, are finely diced to create mirepoix, the classical French base for soups, sauces, and vegetable stock. This trio is also the basis for much Cajun cuisine. Celery seeds are used widely in Indian cuisine. The seeds can also be crushed and mixed with salt to form “celery salt,” which is a popular seasoning, notably in Bloody Mary cocktails.

Both celery and celeriac are biennial plants. While they need to be transplanted outdoors around the time of the last frost, if the weather heats up and then cools down sharply, they may respond as though they’ve had their first winter and bolt to set seeds. Ideally, they will grow gradually as the soil warms in spring.

Celery requires a great deal of growing time, more so for celeriac. It is recommended to grow a cover crop of hairy vetch over the bed, and till it under three weeks prior to setting out celery or celeriac transplants, as both varieties need a rich, deep soil and plenty of potassium and nitrogen. Adding lime after tilling in the vetch is a good idea, because celery wants a pH of 6.0 to 7.5. Celery will also benefit from the calcium deposited by the lime. The added organic matter from the vetch will enhance the water-retaining capacity of the soil, which is useful because celery requires copious amounts of water. Wild celery, from which both celery and celeriac were bred, prefers growing in swampy, waterlogged areas.

It is the high water content of celery that makes it so useful in weight-loss diets. While it provides ample dietary fibre, some people believe that raw celery is so difficult to digest that it has “negative calories” — the body burns more calories in digesting the fibres than it absorbs. In any event, celery can consist of as much as 95% water.

Celeriac is grown as a root vegetable to the size of a grapefruit—about 12cm (5”) in diameter — though much of the “bulb” grows above ground. The benefit of celeriac over other root vegetables is that it contains hardly any starch. The roots can be stored for as long as four months if kept cool and humid so they don’t dry out. The edible portion of celeriac is not a root, but a hypocotyl — an organ in which the plant can store food for the following year.

People unfamiliar with celeriac are unlikely to buy one on impulse in the grocery aisle, as they really don’t look very appealing. But they are both delicious and versatile in the kitchen. Classic recipes for them abound, and they are worth getting to know better.

Like artichokes, when celeriac is cut, it discolours quickly. Just place cut pieces directly into a bowl of cold water with a little lemon juice added to maintain its white appearance. If you’re not familiar with celeriac, try a simple coleslaw of julienned celeriac, some grated carrot, and a mayonnaise/mustard dressing. It’s tasty and unique enough to impress your friends. It’s also good to add to soups for a light crunch or cooked as a mash.

Chinese celery has the same, mild, pleasantly acrid aroma as the celery most familiar in North America, but from a more elegant plant. The stems of Chinese celery are longer, crispier, and hollow along their length. This type of celery wants cooler growing conditions. Direct sow seeds around the middle of April by just pressing them lightly into the surface of the soil, and keep the planting area moist.

The Umbrian town of Trevi, in Italy, celebrates Sagra de Sedano Nero each October — the festival of “black celery.” Sedano Nero is actually a very dark celery cultivar that is grown (under the protection of local law) in the region of Trevi. It grows like a tall celery would, but with the colour of parsley. Dishes featuring this local celery are featured, sometimes in high gastronomic style, and the gathering allows local growers to show off the rest of their harvests.

How to Grow Celery and Celeriac:

Difficulty: Moderately easy. Neither celery nor celeriac is well suited to container growing.

Timing: Start indoors from February to April (12 weeks before last frost is best), or direct sow April/early May.

Sowing: Simply press the seeds into the surface of the soil, and keep very moist. Celery needs light, moisture, and warmth to germinate, and germination is slow. Seeds may take two weeks to sprout.

Soil: Celery is a heavy feeder and needs rich, moist soil in full sun. Add compost to soil and band ¼-½ cup complete organic fertilizer per 1.5m (5’) of row. Consider preparing celery beds by planting a cover crop of hairy vetch, as described above. Aim for a pH of 6.0 to 7.5.

Growing: Transplant when 10-12cm (4-5”) tall, in mid-May or June. Water frequently. Premature bolting results from young plants being exposed to temperatures below 13°C (55°F) for several days.

Harvest: Pick individual stalks as needed, or cut the whole head at the soil surface. If winter isn’t too cold, celery will stand in the garden until spring, allowing light pickings for soups and salads.

Storage: Celery will keep for a surprisingly long time — at least several weeks in a root cellar. Celeriac can be kept into the following summer under ideal conditions.

Seed info: In optimum conditions at least 75% of seed will germinate. The CFIA minimum standard for celery germination is 55%, which is relatively low for vegetable seeds. Celery seeds may also take 2 weeks to germinate. Soil temperature for germination: 15-24°C (60-75°F). Usual seed life: 3 years.

Growing for seed: If you intend to plant the seeds, isolate each variety by 500m.

Pests & Disease: Good disease prevention measures include crop rotation and aphid control. The larva of the carrot rust fly is an occasional celery pest—they burrow into the heart and stunt or kill the plant. Good companion plants include beans, Brassicas, all onions, spinach, and tomatoes. Avoid planting celery near corn, as they will compete for nutrients and moisture. Read more about Companion Planting.