Overwintering guide
How to overwinter black ash
Winter watering
No winter watering needed in open ground. Containers only need water in long dry, frost-free spells.
The mistake that kills black ash in winter
Cutting black ash 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 black ash care
Overwintering black ash — FAQ
Does black ash need to come indoors for winter?
Black Ash is hardy to roughly USDA zone 2 — winter lows around -46°C. That means it can stay outside all winter in most temperate gardens. Black Ash 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 black ash for winter?
Tidy and mulch in late autumn; leave the plant undisturbed until spring.
How often should I water black ash in winter?
No winter watering needed in open ground. Containers only need water in long dry, frost-free spells.
What kills black ash over winter?
Cutting black ash 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.