Celeriac

Celeriac: plant 35 cm (14 in) apart in the row and 45 cm (18 in) between rows, 1 per square. No known bad neighbours.

Key facts

Spacing in the row	35 cm (14 in)
Between rows	45 cm (18 in)
In a 30 cm (1 ft) square	1 per square
Sun	Full sun, 6–8 hours a day
Root depth	25 cm (10 in)
Height when grown	45 cm (18 in)
Crop rotation group	Roots and onions
Support	None needed

Sowing and germination

How it is started	Started in trays
Seeds per hole	3
Plants kept after thinning	1
Sowing depth	0.2 cm (0.1 in)
Soil temperature	from 15 °C, best 20–24 °C
Days to emerge	7–12 days
Light while germinating	Needs light, barely cover
Before sowing	nothing needed
When to plant	Indoors 10 weeks before the last frost; outdoors after the last frost; soil at least 12 °C

From seedling to plant

After emergence	12–20 °C; take the cover off as soon as they show
Pricking out	at 2 true leaves
Takes transplanting	Only with care, keep the root ball
Life cycle	Biennial, harvested in its first year
Cold tolerance	Takes a light frost → hardy, takes hard frost
Soil	Light, sandy, free draining, pH 6–7
In a pot	10 L, 30 cm (11.8 in)
Watering	Water when the soil is dry two fingers down; while roots swell
Feeding	Hungry; at planting, while growing
Support and training	None needed

Harvest and planning

Days to first harvest	110–140 days, from planting out
Ready when	The shoulder shows at the right size
Harvest window	All at once, 3–6 weeks
Typical yield	0.5–1 kg per plant
Botanical family	Apiaceae
Watch out for	Carrot fly, slugs and snails

Plan Celeriac in your garden

Open the free planner, drop Celeriac onto a bed and see how many plants fit.

Start Planning Your Garden

Sowing and harvest

Sow indoors	Feb–Mar
Plant out	May
Harvest	Oct–Nov

My dates for this crop

My country Last spring frost where I live

Give the date once and this page, the sowing calendar and the planner all follow it.

Months for a temperate climate: about a month later in the north and a month earlier in the south. Give your own last frost date for exact dates.

What to plant next to Celeriac →

From the same family

Plants of the Apiaceae family share diseases and pests, so they follow each other in the rotation only after a break.

Grown much the same way

Crops that need about the same room and care, from another family.

Sources

The values on this page marked as checked come from these sources: spacing, sowing depth, germination, soil, timing and safety notes, each against the source named here.

Soil Temperature Conditions for Vegetable Seed Germination (GN 154, after J.F. Harrington, UC Davis) — UC Cooperative Extension, UC ANR for: days to emerge; checked 2026-10-30

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