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