Growli

Overwintering guide

How to overwinter autumn squill

Verdict
Stays outside
When
Tidy and mulch in late autumn; leave the plant undisturbed until spring.
Hardiness
Autumn Squill is hardy to roughly USDA zone 5 — winter lows around -29°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 autumn squill in winter

Cutting autumn squill 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 autumn squill care

Overwintering autumn squill — FAQ

Does autumn squill need to come indoors for winter?

Autumn Squill is hardy to roughly USDA zone 5 — winter lows around -29°C. That means it can stay outside all winter in most temperate gardens. Autumn Squill 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 autumn squill for winter?

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

How often should I water autumn squill in winter?

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

What kills autumn squill over winter?

Cutting autumn squill 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.