Overwintering guide
How to overwinter hemlock water parsnip
Winter watering
No winter watering needed in open ground. Containers only need water in long dry, frost-free spells.
The mistake that kills hemlock water parsnip in winter
Cutting hemlock water parsnip 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 hemlock water parsnip care
Overwintering hemlock water parsnip — FAQ
Does hemlock water parsnip need to come indoors for winter?
Hemlock Water Parsnip is hardy to roughly USDA zone 3 — winter lows around -40°C. That means it can stay outside all winter in most temperate gardens. Hemlock Water Parsnip 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 hemlock water parsnip for winter?
Tidy and mulch in late autumn; leave the plant undisturbed until spring.
How often should I water hemlock water parsnip in winter?
No winter watering needed in open ground. Containers only need water in long dry, frost-free spells.
What kills hemlock water parsnip over winter?
Cutting hemlock water parsnip 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.