February–August, depending on cultivarSow in a bright position that is not hot. A warm loft can be too hot.
- Germination and temperature
- Germinate in cool, bright conditions; much lettuce germinates poorly above about 25 °C.
- After emergence
- Keep emerged lettuce bright and well ventilated; prevent high greenhouse temperatures and drying out.
- Pricking out and potting on
- Sow in modules or prick out manageable seedlings into individual cells. Keep the root ball intact when planting out.
- Hardening off and planting out
- Gradually acclimatise indoor-raised plants to sun, wind and outdoor temperatures; shelter them again on cold nights. Plant out sturdy young plants; keep the growing point clear and protect against slugs and snails.
Choose a spring, summer or winter cultivar. Celtuce has a different harvest aim from heading lettuce; follow its own cultivar window.
Sources and use
RHS · sla ↗Britse teeltrichtlijn voor een gematigd klimaat; de genoemde perioden zijn richtlijnen voor Nederland en Vlaanderen.
Magic Garden Seeds · Stengelsla / Chinese aspergesla ↗Nederlandse producent of teeltbron; de rasinstructie blijft leidend.
Feggies · Aspergesla zaden 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.