March; celery mid-March–early AprilStart indoors in good light and prevent a cold-induced growth check in young plants.
- Germination and temperature
- Germinate in warm, bright conditions according to species guidance. Protect young plants from prolonged cold; keep celeriac above about 10 °C.
- After emergence
- Give seedlings light immediately after emergence. A dark loft needs suitable grow lights; warmth alone is insufficient. Ventilate and keep the compost moist without saturating it.
- Pricking out and potting on
- Sow fine seed shallowly according to the packet; prick out manageable seedlings into individual modules.
- Hardening off and planting out
- Gradually acclimatise indoor-raised plants to sun, wind and outdoor temperatures; shelter them again on cold nights. Plant in late spring or early summer during milder weather. Keep the heart of celeriac above ground.
Celeriac has a long season. Celery and leaf celery have different harvest aims; use their own cultivar instructions.
Sources and use
RHS · knolselderij ↗Britse teeltrichtlijn voor een gematigd klimaat; de genoemde perioden zijn richtlijnen voor Nederland en Vlaanderen.
De Bolster · Snijselderij Gewone Snij ↗Nederlandse producent of teeltbron; de rasinstructie blijft leidend.
Feggies · Snijselderij 'Gewone Snij' Biologisch ↗Nederlandse producent of teeltbron; de rasinstructie blijft leidend.
Guideline periods for the Netherlands and Flanders. Check the variety, available light, soil and measured temperatures. Greenhouse heating does not guarantee enough winter light.