Overwintering guide
How to overwinter spider iris
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 spider iris in winter
Bringing spider iris 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 spider iris care
Overwintering spider iris — FAQ
Does spider iris need to come indoors for winter?
Spider Iris is hardy to roughly USDA zone 9 — winter lows around -7°C. That means it takes cool conditions but not a real freeze. Spider Iris 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 spider iris for winter?
Move under cover before the first hard frost; back outside after the last spring frost.
How often should I water spider iris in winter?
Water only occasionally — enough that the rootball never dries out completely, no more. No feeding until spring growth begins.
What kills spider iris over winter?
Bringing spider iris 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.