Overwintering guide
How to overwinter marsh valerian
Winter watering
No winter watering needed in open ground. Containers only need water in long dry, frost-free spells.
The mistake that kills marsh valerian in winter
Cutting marsh valerian 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 marsh valerian care
Overwintering marsh valerian — FAQ
Does marsh valerian need to come indoors for winter?
Marsh Valerian is hardy to roughly USDA zone 4 — winter lows around -34°C. That means it can stay outside all winter in most temperate gardens. Marsh Valerian 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 marsh valerian for winter?
Tidy and mulch in late autumn; leave the plant undisturbed until spring.
How often should I water marsh valerian in winter?
No winter watering needed in open ground. Containers only need water in long dry, frost-free spells.
What kills marsh valerian over winter?
Cutting marsh valerian 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.