Celeriac is a biennial in the Umbelliferae family that resembles celery. It is grown for its brownish root, which looks like a very bumpy, large turnip, has a celery taste when cooked, but lacks stalk celery’s stringiness.
It is also called turnip rooted celery or knob celery, and is usually about 4 inches in diameter at maturity, but is often harvested earlier than full maturity for a more tender crop.
It is usually eaten cooked, rather than raw, and used in Remoulade sauce or in soup or stews. It may also be used both raw and cooked in salads.
Although used less often, the leaves may be harvested and eaten anytime.
Celeriac is a cool season crop, grown like celery, but blanching is not required.
It has a potential for high yields, and good storage. It is relatively trouble free but slow to grow.
Varieties include Giant Prague, Early Paris, Large Smooth Prague, Dolvi, Zwindra, and others.
Sow shallowly and keep moist. It’s best to start indoors 8-12 weeks before the last frost. Set out 8-12 inches apart when danger of frost is past.
Treat as celery for soil and fertilizer. Best planted in soils of high fertility. Prefers rich muck, sandy loan or other soils with high water holding capacity and good drainage. Tolerates pH of 6.0 to 7.6. Uses a lot of N, P and K.
It’s recommended to use supplemental nutrient applications averaging 300 kg N, 75 kg P and 250 kg K per hectare on mineral soils, and less nitrogen on muck soils.
Rapid plant grow toward the latter period of development may magnify minor nutrient deficiencies. Boron deficiency results in cracked stems and brown checking symptoms; calcium deficiency causes blackheart; inadequate magnesium results in leaf chlorosis. These minor nutrients can be applied by topical spray for rapid response, but soil applications made in advance are best.
Post-Harvest and Packing
Celeriac is harvested about 110 days after seeding, and 80-90 days from transplanting, or when bulbous stems are about 10 cm in diameter.
Roots are best harvested when about 2 inches in diameter. The plants are lifted, tops and roots trimmed, and stored in refrigeration at 32 degrees F with 90-95 percent relative humidity.
Under these conditions can keep 3-6 months.