These species have heterophyllous leaves � the summer leaves are carnivorous while the winter leaves are succulent and not carnivorous. The plants like warm humid conditions when in the summer, carnivorous state. During the winter when they are in the succulent state they should be kept cooler and drier.
Mexican Pinguicula are NOT bog plants and should not be grown like bog plants. In the wild, many Mexican Pinguicula grow in seasonal fog forests on limestone cliffs and tree trunks. Some grow in moss, others just cracks in the rocks.
To maintain these species long term they need seasonal light cues and the seasonal changes in moisture. The seasonal changes are cued by light, not moisture. When the plants have carnivorous leaves they need to be kept moist and enjoy high humidity. When they have succulent leaves, usually during late winter, the plants need much less water. Keep the soil lightly damp. Some species can be totally dry if the air is very humid.