Mammillaria discolor

Overwintering and light

J. Gil's account recommends overwintering at 7–10°C. References to a minimum of −6°C and a 22°C threshold when moving from sun to shade have no stated measurement protocol and do not establish safety thresholds. [Gil b.d., file p. 1, 2, 3, 4]

There is no comparative experiment. Identification of the local form remains important when comparing observations.