Phragmipediums, what happens to old growths?

[krienschmidt]

Hi everyone, my question is about Phragmipedium orchids. I have a Phrag that has yellowing and dying old growths. There are 3 new growths, (one that did bloom) that seem to be good but 3 older growths (at least over a year) that have been gradually turning yellow from the tips down till eventually they are gone. I have been trimming them back as they yellow down. Is this normal for the old growths to die off? Should I repot to remove old growths and possible dead roots? Thank you for any ideas and help.