That is normal for the older stems to die. Just remove them.
You will have to dig it up for the winter so you could just leave it where it is for now or dig and put in a pot so you are not digging and moving it too many times.
Store dry over the winter in garage or basement that doesn't freeze. Bring out next spring.
Do a search on this forum and several discussions will be found.

I would leave it where it is. Make sure it gets enough water. Do you have it in the ground or a pot? Next year you can plant it in full sun.
Susan

Thanks for the responses. Right now its in the ground and i was planning on digging it up in the fall. Now the greenhouse owner was telling me when i brought it in, place near a window, make sure gets plenty of water etc, and that it would continue to bloom all winter? But it sounds like i should let it go dormant? I have a feeling hes just getting older now and his memory might be going a bit. But as of now it the foilage looks great. Its just the shoots come up, and then turn yellow and brown before they ever bloom. So so far i have only gotten one bloom. Would not getting enough sun cause the new shoots to not bloom? Sorry for all the questions, and i will do a search too and see what i can find. Thanks again for all your help. Tami