It looks like your old leaves are just falling off.

Yes, old leaves.

Even so, it looks like that's a lot of plant for a relatively small pot. Are you keeping up with the plant's water needs?

I always keep the soil wet...I got this plant recently and upgraded the pot to what I thought was a great improvement over the original! So how much bigger should it be?

Is this normal that the leaves on theMandevilla vine is getting yellowish and black spots on leaves this time of year, Aug. 2011. I give it water every other day ..

Thank you, Karin