P. iocastum is found in the extreme south-western Cape Province, growing mainly in high mountains, but also at lower altitudes. Because much of the higher altitude is covered in snow occasionally during the winter months, it flowers between September and January, later than usual for pelargoniums in the Cape.
The meaning of the name ‘iocastum’ is not known.
The plant is easy to propagate from seeds or cuttings and requires a well drained, moist compost. It also requires cooler conditions that usual for pelargoniums.
