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