If you've suddenly changed its cultural conditions, as you intimate in the above, then it's almost a natural reaction, or plant shock, that's causing them to shed their leaves. You can't give them too much heat, all things considered, so I'd guess it's the shock from being shown full sun too fast - if you acclimate it to full sun you'll be fine.

I would agree with harris..its just having shock response from indoor temps to outdoor heat and sun. Adeniums love heat and sun but when kept indoors they need to be acclimated to it gradually or they will loose their leaves, scream bloody murder, and play dead for a week before they acclimate and start to come back from the shock. Your plant will grow new leaves in some time, maybe try moving it to some shade for a few days and gradually move it back into the sun over time.

MORE sun and heat. Burn it a little.

Thanks for your comments, I took the plants back inside next to a window. They seem happier so far, fewer yellow leaves, some buds are blooming. I thought desert rose was easy to grow. I have many other succulents that are so easy. I hope I don't kill them.

One thing to keep in mind also when you are messing with the leaves or the plant in general, the sap is very caustic..do not get the sap on your fingers then touch your face, eyes, nose, mouth ....you get the point. I did a trim job on one of mine in the spring and was not paying attention and rubbed my face..oh wow never again!

Mary

Mary, thanks for the advice. I haven't had a bad reaction to sap yet but I'll watch out. I have several poisonous plants like euphorbia and plumeria. But they're so pretty =)

Well i have had it on my hands many times with no reaction at all but when it came in contact with my face I had a nasty reaction. I think our hands have a tougher skin and its harder to absorb through them.

I also have several toxic plants. plumerias included...they are lovely to raise we just have to be sensible when handling them.

A note on the leaves turning yellow and dropping. Also remember that leaves do not last forever either, they do in time die off and drop as new ones take over. That is a natural process. Somehting I think we forget when it comes to adeniums because we love to see how nice they look.

I have a Desert Rose that I bought about 1 year ago. When I bought it, it had a beautiful flower. Once the flower dropped off, it never flowered again. The leaves turn brown at the tip and eventually fall off. It lost all of its leaves at one point. Now the leaves are growing, but they start to turn brown at the tip and eventually fall off. I water the plant 1X/week and I water on the light side. I had been watering it 2X/week, but I was told that I was giving it too much water. I don't know what to do with it anymore. I thought these were easy to raise...but I have had alot of trouble with it. Please help me!! Thank you so much.
Liz

Hi Liz, I have the same problem.

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By springpaintings
After the leaves turned yellow and fell off the stems stayed bare. So I cut them off hoping they'll branch out more. So far nothing happened.

An update to my previous post...
So after I brought the two new plants inside next to a window, they seemed happier. They bloomed a little and the leaves stopped turning yellow and falling off. There're no new buds though. Does anyone know the growing cycle of desert rose? Do they flower year round?

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By springpaintings

Adeniums generally flower twice a year, spring and fall..but they need the right conditions to flower, they love heat, sun and water in hot weather....all mine stay outside in full sun all summer. I fertilize mine about every 2 weeks, but i am not fertilizing anymore now as it will be fall soon and they will go dormant after this flowering.

Mine do not go dormant but will stop flowering for the winter. I will occasionally get a flower or 2 in the winter. Mine peaks flowering in July-August. I will get sporadic flowers year round.

Not sure what zone you are in but adeniums need a dormant period in the winter to rest.

Mary

For the comment on the leaves turning brown prune it

not sure if you noticed - those posts are from 2011

I also have yellow leaves on my desert rose, it has been watered but since then it seems as though more leaves have turned yellow, could it be my water? I use distilled water. Also my son brought it from lowes in flodida and i live in new jersey, can this be the problem or can it cause other problems in the future? Help, i really like this plant.

I HAVE A YELLOW DESERT ROSE. I HAD IT ON A COVERED DECK. WHEN I BROUGHT IT INSIDE NEXT TO A WINDOW WITH INDIRECT LIGHT, ALL OF THE LEAVES TURNED YELLOW AND FELL OFF EXCEPT THE VERY TOP. IT IS TALL AND BARE. ANY IDEAS? SARAH GEORGIA

Often suggested is to look in older threads for information Old threads come back to surface ( like this one ) is probably the result of following a suggestion.

Anyhoo ( & ironic) 2011( maybe 2010) was the Apx starting year that certain plants had separated from the C&S plant forum. Adenium being one of the plants that where relocated to a different area of the forum ( plant specific) has it's own topic full of threads that can be found by following this link. http://forums.gardenweb.com/forums/adenium.

Good luck

I bought a desert rose plant with buds almost ready to open but after some days they did not open but just fell off, don't know what the problem is.

Check for bugs around where the buds use to be.Can you take a pic of the plant:)?

As mentioned above, maybe try the Adenium forum itself for species specific info!