Overwintering guide
How to overwinter cos romaine lettuce
Winter watering
No winter watering needed in open ground. Containers only need water in long dry, frost-free spells.
The mistake that kills cos romaine lettuce in winter
Cutting cos romaine lettuce hard back in autumn "to tidy up". That removes the growth that shelters the crown, and on some plants removes next season's flower buds entirely.
More cos romaine lettuce care
Overwintering cos romaine lettuce — FAQ
Does cos romaine lettuce need to come indoors for winter?
Cos Romaine Lettuce is hardy to roughly USDA zone 2 — winter lows around -46°C. That means it can stay outside all winter in most temperate gardens. Cos Romaine Lettuce is properly hardy and overwinters outside without fuss. Tidy away anything dead or diseased, apply a mulch over the crown to steady soil temperatures, and otherwise leave it alone — many hardy plants actually need a cold period to flower and grow well the following year. Save hard pruning for the right season rather than doing it in autumn.
When should I move cos romaine lettuce for winter?
Tidy and mulch in late autumn; leave the plant undisturbed until spring.
How often should I water cos romaine lettuce in winter?
No winter watering needed in open ground. Containers only need water in long dry, frost-free spells.
What kills cos romaine lettuce over winter?
Cutting cos romaine lettuce hard back in autumn "to tidy up". That removes the growth that shelters the crown, and on some plants removes next season's flower buds entirely.