Are those Mulberry vines in his cage? I used some I found at a craft store and after a while they rotted really bad and turned black. I would not recommend them for very long. Because of this, I have switched to the Fluker's Bend-A-Vine. They are a lot easier to clean and won't rot.
I should also say, they rotted where water was able to accumulate on them. Mainly in an area where 2 of the vines were overlapped and tied together. Either way, they are cool vines, but they are super porous and absorb alot of water and bacteria.
Maybe I just didn't have good luck with them.