Overwintering guide
How to overwinter hart's pennyroyal
Winter watering
No winter watering needed in open ground. Containers only need water in long dry, frost-free spells.
The mistake that kills hart's pennyroyal in winter
Cutting hart's pennyroyal 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 hart's pennyroyal care
Overwintering hart's pennyroyal — FAQ
Does hart's pennyroyal need to come indoors for winter?
Hart's Pennyroyal is hardy to roughly USDA zone 6 — winter lows around -23°C. That means it can stay outside all winter in most temperate gardens. Hart's Pennyroyal 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 hart's pennyroyal for winter?
Tidy and mulch in late autumn; leave the plant undisturbed until spring.
How often should I water hart's pennyroyal in winter?
No winter watering needed in open ground. Containers only need water in long dry, frost-free spells.
What kills hart's pennyroyal over winter?
Cutting hart's pennyroyal 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.