Overwintering guide
How to overwinter climbing onion
Winter watering
Water only occasionally — enough that the rootball never dries out completely, no more. No feeding until spring growth begins.
The mistake that kills climbing onion in winter
Bringing climbing onion into a warm living room. Too much winter warmth forces weak, pale growth that collapses when it goes back outside — cool and bright beats warm and dim.
More climbing onion care
Overwintering climbing onion — FAQ
Does climbing onion need to come indoors for winter?
Climbing Onion is hardy to roughly USDA zone 9 — winter lows around -7°C. That means it takes cool conditions but not a real freeze. Climbing Onion will take cool conditions but not a hard freeze, so the aim is a frost-free winter rather than a warm one. An unheated greenhouse, porch, conservatory or bright garage all work well. Keep it cool, bright and on the dry side, and it will hold steady until growth restarts in spring.
When should I move climbing onion for winter?
Move under cover before the first hard frost; back outside after the last spring frost.
How often should I water climbing onion in winter?
Water only occasionally — enough that the rootball never dries out completely, no more. No feeding until spring growth begins.
What kills climbing onion over winter?
Bringing climbing onion into a warm living room. Too much winter warmth forces weak, pale growth that collapses when it goes back outside — cool and bright beats warm and dim.