Vegetable · Apiaceae
When to plant celeriac
A long season for one root, and worth it. Needs constant moisture from start to finish - any check produces a small woody knob.
Start seed indoors
10 weeks before
Counted from your last spring frost.
Plant out
2 weeks after
Counted from your last spring frost.
Days to maturity
110-140
From planting out to a first picking.
Those weeks become real dates once you name a place.
Timing, in frost-relative terms
Seed packets rarely give calendar dates, because a date that suits one latitude is wrong at another. They give offsets from the last spring frost instead, and those offsets are what make celeriac plantable anywhere.
- Start seed indoors 10 weeks before the last frost.
- Plant out 2 weeks after the last frost.
- Expect 110–140 days to maturity, counted from planting out.
Getting the timing right
Start indoors 10 weeks before the last frost and plant out after it, keeping the crown at soil level rather than buried. Remove the lower leaves in late summer so the root swells cleanly.
Frost tolerance
Stands to about -8C in the ground and improves with a touch of frost, so it can be left and lifted as needed well into winter.
Classified as hardy, with damage expected below -8°C (17.6°F)17.6°F (-8°C).