Growli

Overwintering guide

How to overwinter eryngium giganteum 'silver ghost'

Verdict
Stays outside
When
Tidy and mulch in late autumn; leave the plant undisturbed until spring.
Hardiness
Eryngium giganteum 'Silver Ghost' is hardy to roughly USDA zone 4 — winter lows around -34°C. That means it can stay outside all winter in most temperate gardens.

Winter watering

No winter watering needed in open ground. Containers only need water in long dry, frost-free spells.

The mistake that kills eryngium giganteum 'silver ghost' in winter

Cutting eryngium giganteum 'silver ghost' 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 eryngium giganteum 'silver ghost' care

Overwintering eryngium giganteum 'silver ghost' — FAQ

Does eryngium giganteum 'silver ghost' need to come indoors for winter?

Eryngium giganteum 'Silver Ghost' is hardy to roughly USDA zone 4 — winter lows around -34°C. That means it can stay outside all winter in most temperate gardens. Eryngium giganteum 'Silver Ghost' 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 eryngium giganteum 'silver ghost' for winter?

Tidy and mulch in late autumn; leave the plant undisturbed until spring.

How often should I water eryngium giganteum 'silver ghost' in winter?

No winter watering needed in open ground. Containers only need water in long dry, frost-free spells.

What kills eryngium giganteum 'silver ghost' over winter?

Cutting eryngium giganteum 'silver ghost' 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.