why does my rollina deliciosa keep shedding leaves AND branches?

[Daintree]

I have a 3 yr old Rollina deliciosa in a 25 gallon pot.  It lives in my greenhouse along with all my other tropicals and is in part shade.  It continuously sheds leaves (maybe three leaves a day).  The leaves start turning yellow then drop within a day.  Also, it puts out a lot of branches that live for a few months, then turn brown and die.  It immediately puts out another branch directly below the dead branch.  When the day length gets short, it will shed almost all of its leaves at once, so I try to keep it under lights in the winter.

But overall, it looks quite healthy - dozens of healthy green branches and hundreds of leaves.  It is always putting on new leaves.  Maybe 5% of the leaves drop, but it looks like a lot when see them on the floor.

It gets a balanced fertilizer and weekly water, although it seems to be one of my "thirstier" plants, in that the potting soil does dry out rather quickly.  I have given it iron with now obvious changes.

Any ideas about what could be going on with it?

Thanks!

Carolyn

[luc]

They do that at my place also shedding all the leaves but new ones grow immediately and it starts flowering . I also have a lot of die back from branches , doesn't
 seems to be a problem ....

[Daintree]

Thanks Luc!
Maybe that is just what they do...

Carolyn

[michsu]

I have a lot of dead branches from last year too that don't have leaves.. is it safe to remove them? It's been in the ground since Sep 2014.. about double in size? The leaves seem to be much better around December though compared to the summer.. The only thing is this year the temperatures have been much cooler.. we are still getting 60s and 70s as day highs.. years before it should be just like this week (mid 80s) by now..

Last Weekend - around same time as May 2015 picture


December 2015


May 2015


December 2014