This desert rose, Adenium obesum, was put on a window sill on top of a radiator, and did well for approximately 10 days.
Then I left for the Holydays. I left the plant with extra water and no heating. The temperature must have gone under 10ºC, (50°F), but it wasn't watered any more during my absence of 15 days.
On my return, as you can see in the pictures, I found it wilting.
I thought it might be a watering problem, as the soil was completely dry, so I watered it, making sure all the water drained. I also moved it to a window sill where there is no radiator. Now the roots are moist, if I touch them from the bottom holes of the pot.
The soil is clearly peat based, and it looks like the bottom is moist, but the top quite dry. What should I do? Water it more? Leave it without water for a while? I really have no idea!
My house has a temperature of approximately 15-16ºC during the day, sometimes 17-19ºC when I turn on the heat at night. The aspect of the window is south-west, but it doesn't get much direct sunlight, about 3-4 hours when it's sunny. I am in the UK, Bristol.