How to grow celery

Celery is a biennial in the carrot family, grown as an annual for its crisp, upright petioles. The plant rises as a dense cluster of ribbed stalks from a compact base, reaching 18 to 24 inches tall with ferny, aromatic foliage at the crown. Leaves and root are also edible. In the bed, it is a demanding presence, requiring rich, moisture-retentive soil and a steady water supply throughout, because its roots, though capable of extending two feet down, stay concentrated in the top six inches and are poor foragers by nature.

The hardest part of growing celery well is maintaining even soil moisture from planting through harvest; Utah State University Extension notes that any water stress turns petioles stringy and strongly flavored, a defect that cannot be corrected later. The real failure mode for second-year growers, however, is premature bolting: gardeners who transplant early to steal time often set plants into ground where nights still regularly fall below 40°F, and the plant responds to that sustained chill as a vernalization cue by sending up a seed stalk, ending any harvest at all. University of Massachusetts Extension notes that this bolting response sets in when temperatures below 40°F persist for ten to fourteen days.