MarchStart 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
Royal Horticultural Society · Knolselderij kweken ↗Soort- of productgebonden bron; buitenlandse perioden zijn geen vaste Nederlandse zaaidatum.
Velt · Knolselder bewaren en verwerken ↗Soort- of productgebonden bron; buitenlandse perioden zijn geen vaste Nederlandse zaaidatum.
Guideline periods for the Netherlands and Flanders. Check the variety, available light, soil and measured temperatures. Greenhouse heating does not guarantee enough winter light.