Light bulbs hang on to blowing after a few days? ...

What colours of pigface (Mesembryanthemum) can you acquire?
Answers:    Some details would be helpful, but since you put this within Garden & Landscape I would guess that you have a leach in the part somewhere. Are you using outdoor rated bulbs?
How to grow platycerium plants within a greenhouse?
Do you own a water trickle somewhere? Are the bulbs too high wattage? Please telephone call an electrician about that. Take strictness.