Overwintering guide
How to overwinter butterfly bush 'black knight'
Winter watering
No winter watering needed in open ground. Containers only need water in long dry, frost-free spells.
The mistake that kills butterfly bush 'black knight' in winter
Cutting butterfly bush 'black knight' 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 butterfly bush 'black knight' care
- Overwintering butterfly bush — the species this cultivar belongs to
- Full butterfly bush 'black knight' care guide
- Butterfly Bush 'Black Knight' temperature range
- How often to water butterfly bush 'black knight'
- How to prune butterfly bush 'black knight'
- Common butterfly bush 'black knight' problems & fixes
- Best plant identifier apps — tested and ranked
Overwintering butterfly bush 'black knight' — FAQ
Does butterfly bush 'black knight' need to come indoors for winter?
Butterfly Bush 'Black Knight' is hardy to roughly USDA zone 5 — winter lows around -29°C. That means it can stay outside all winter in most temperate gardens. Butterfly Bush 'Black Knight' 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 butterfly bush 'black knight' for winter?
Tidy and mulch in late autumn; leave the plant undisturbed until spring.
How often should I water butterfly bush 'black knight' in winter?
No winter watering needed in open ground. Containers only need water in long dry, frost-free spells.
What kills butterfly bush 'black knight' over winter?
Cutting butterfly bush 'black knight' 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.