How to Grow Celeriac: Planting, Spacing, Care & Harvest

Quick answer

Start indoors as early as 10 weeks before last frost (UC). Transplant on/after last frost (UC/UKY). Not the same crop as stalk celery.

Celeriac at a glance

PlantStart indoors: 10 wk before last frost; Transplant: last frost
SunUC: full sun or very light shade; fertile, humus-rich, moisture-retentive soil.
SpacingUKY: set plants 6 to 8 inches apart in rows 24–36 inches.
Days to harvest~100–150 days (UC)
-11-10-9-8-7-6-5-4-3-2-1LF+1+2+3
■ Start indoors   ■ Plant out   ■ Harvest
Weeks relative to last frost (LF). Colored weeks show when our ZIP planner schedules each step.
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Updated

Planting dates for your ZIP: the ZIP planting planner counts each window from your local frost dates.

Organic pests and diseases: see also organic pest control. Use any product as the label directs.

Not stalk celery: celeriac (Apium graveolens var. rapaceum) is grown for the swollen root. See also how to grow celery.

Celeriac root
Celeriac (Apium graveolens var. rapaceum). Photo: Radim Dudek, Wikimedia Commons, CC BY-SA 3.0 (resized).

Planting timing

UC Master Gardeners of Sonoma County: “Sow seed indoors as early as 10 weeks before the average last frost date in spring.” “Plants can go into the garden … on the average date of last frost …” (UC Sonoma celeriac) University of Kentucky CCD: sow indoors about 10–12 weeks before transplanting; “Transplant outdoors … after last frost has passed.” (UKY celery and celeriac)

Depth and spacing

UKY: set plants 6 to 8 inches apart in rows 24–36 inches. UC: about 10–12 inches apart. Hill soil over the swollen root to blanch (UC).

Sun, soil and water

UC: full sun or very light shade; fertile, humus-rich, moisture-retentive soil. Shallow roots need even moisture. Avoid cool soil at planting or plants may run to seed without a large root. Plan on about 100–150 days to maturity (UC).

Care

UKY: exposure to nights below 40°F and days below 50°F for about 10 days can cause premature bolting. Plants survive light frosts; celeriac is more frost-tolerant than celery. Prefer compost and soil test over product rates.

Harvest

UC: lift roots when about 3–4 inches across; cut stems close to the knobby root. Flavor can improve after a light frost.

Pests and diseases

UKY notes early and late blight on celery (can also infect celeriac); buy clean seed and rotate. Cultural moisture and airflow first; use any product as the label directs.

Related: celery · ZIP planner · organic pest control

Frequently asked questions

When do I start celeriac?

Indoors as early as 10 weeks before last frost (UC). Transplant at last frost (UC/UKY).

Is it the same as celery?

Same species group, different crop — celeriac is the root form; see the celery grow guide.

Will cold make it bolt?

UKY: ~10 days of cold nights/days can trigger bolting — harden by reducing water, not by chilling.

More grow guides: All grow guides

Sources