Overwintering guide
How to overwinter alisma plantago-aquatica
Winter watering
No winter watering needed in open ground. Containers only need water in long dry, frost-free spells.
The mistake that kills alisma plantago-aquatica in winter
Cutting alisma plantago-aquatica 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 alisma plantago-aquatica care
Overwintering alisma plantago-aquatica — FAQ
Does alisma plantago-aquatica need to come indoors for winter?
Alisma plantago-aquatica is hardy to roughly USDA zone 5 — winter lows around -29°C. That means it can stay outside all winter in most temperate gardens. Alisma plantago-aquatica 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 alisma plantago-aquatica for winter?
Tidy and mulch in late autumn; leave the plant undisturbed until spring.
How often should I water alisma plantago-aquatica in winter?
No winter watering needed in open ground. Containers only need water in long dry, frost-free spells.
What kills alisma plantago-aquatica over winter?
Cutting alisma plantago-aquatica 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.