Hi, I must admit I had never heard of desert rose, but have now found out that it is a succulent, it's botanical name is> Adenium obesium, it needs an absolute minimum winter temperature of 50 deg f, but will lose it's leaves at this temp, 60deg f and above, and it may retain the leaves, grow it in a cactus mix which is slightly acid, and in winter water just enough to prevent leaf drop, if your winter temperature outside doesn't match the above, a sunny south facing window inside is fine, if however it's nice and warm all year round, leave it in full sun outside. Derek.
Ps sorry you've had a long wait for a reply.
Pps I somehow managed to put an I in obesum, there isn't one, sorry, Derek.

Thank you Derekm so much for your help in this matter. I need to put it in the right type of soil and maybe I will have better luck with it. My sister's desert rose is ALWAYS blooming beautifully while mine is just there, if you know what I mean. Again, thank you so much for your reply and no worry that I waited for your reply. I am retired so time is not an important issue to me

You're welcome, Derek.