Celeriac is not one of our more popular vegetables, perhaps because it resembles an unwashed horseradish root. Yet beneath its unattractive, unglamorous shell lies a flavorful, crisp, cream-colored, smooth-textured flesh that tastes like celery. It can be used raw in fresh salads or as a cooked vegetable and it is an important ingredient in soups. While it is not much of a seller in the United States, it is very popular in northern Europe. Here at home, fresh celeriac is available every month but June and July.
When harvested, celeriac looks like coarse green celery attached to a rough-looking bulbous root. In late summer and early fall it comes to market usually tied in bunches that have three knobs and with the celerylike greens attached. The greens are too coarse to use raw as table celery, but if they are fresh and have not begun to yellow, they make a fine soup green. After the first frost, the celeriac is shipped to market minus the greens and sold as a root vegetable by the pound.
Select firm medium-sized knobs; small ones have too much waste when peeled and large knobs are apt to be hollow or woody. Pressure on any darker areas of the skin will expose decay that otherwise might be hidden by the rough exterior.
When served raw, the exposed flesh tends to discolor. The discoloration can be retarded by adding a few drops of vinegar or lemon juice. When cooking celeriac, they will be easier to peel after they have been boiled.
Celeriac is a close relative of celery but has an enlarged, edible root. The plant tolerates heavier soil but well drained soil is preferred. Seed can be started early indoors with 3 inch seedlings ready for outdoor planting. Seed may be sown outdoors in early to mid-April. Sow seed 1/2 inch deep then thin or set plants at 4 to 6 inch spacings in rows 18 to 24 inches apart. Blanching is not needed. As the roots enlarge, remove the lateral roots close to the top of the crown. This improves root quality.
Harvest as soon as the roots are large enough.