I love the taste of celery, but not the fussing required to grow it. That’s why I was excited to discover celeriac (Apium graveolens) a number of year ago. Celeriac, or celery root, is grown not for the leaves, but the brown, round, knobby root. Inside the root is a moist, white flesh that tastes just like celery. Celeriac is great roasted with other root vegetables, mashed, sauteed, added to soups, or shredded raw in salads. Celeriac is much more tolerant of the vagaries of the weather than celery and much easier to grow for the novice. Like celery, it needs a full summer of cool, moist soil conditions to grow best.
When to Plant
Celeriac is a slow maturing, cool weather loving crop. Starts seeds indoors 8- to 12-weeks before your last spring frost indoors. Transplant into the garden 2 weeks before the last frost.
Where to Plant
Celeriac grows best in full sun on well-drained fertile soil. Like other root crops, celeriac, can grow with 3 to 4 hours of sun a day, but the roots will take longer to develop. Plant celeriac in beds raised 8 inches tall and 3 feet wide. Root crops grow better in raised beds because the soil isn’t as compacted as in regular beds and the roots can grow to the proper size easier.
How to Plant
Amend the raised bed with compost before planting. Space transplants 4- to 6-inches apart in rows 2 feet apart in the bed. If spaced too closely together, the roots will be small and hairy.
Care and Maintenance
Keep the young transplants well watered. Once established, mulch with an organic material such as straw or untreated grass clippings. The mulch keeps the soil cool and moist, which celeriac loves, and less weedy. If the soil dries out, your roots can develop hollow heart, a condition where the inside of the root has hollow spaces. To produce the largest sized roots, add as small handful of an organic fertilizer, such as 5-5-5, to the bed monthly. However, if your soil is already rich, don’t add more fertilizer or you’ll get hairy roots with a smaller edible portion.
Slugs can sometimes feast on the young transplants. Control these slimy pests with beer traps, organic baits, or by spreading sharp sand, diatomaceous earth, or crushed sea or oyster shells around the plants. These sharp objects prevent slugs from getting to the plants.
Carrot rust fly larvae sometime attack celeriac causing holes in the tops of the roots. Prevent damage from this pest by laying a floating row cover over the planting. This will prevent the adult rust fly from laying eggs on the roots.
Harvest
Celeriac roots really don’t grow under ground, but more accurately on the top of the ground. Once the roots reach 2- to 3-inches in diameter you can start harvesting, usually about 90 days after seeding. Celeriac is tolerant of a few frosts. I like to leave them until after a few frosts has sweetened the roots. Pull the whole plant, cut off and discard the top and roots, peal the knobby exterior to reveal the white, sweet flesh.
Additional Information
The one downside of celeriac is sometimes the root is so knobby it’s almost too much work cleaning and preparing it to use. The solution is to choose varieties that have a smoother skin. ‘Brilliant’ produces small, soft ball-sized roots with a relatively smooth skin. ‘Mars’ is a newer variety that features an even larger root than ‘Brilliant’, but one that stays firm and solid throughout.
Text excepted from the Northeast Vegetable and Fruit Gardening book.
