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