deformed nep pitchers
i've been growing my nepenthes alata for over a year now, and now it has one older vine that is about 5' tall, and 2 younger vines that are about 1' tall. The younger vines have many beautiful red perfect looking pitchers.....but the older vine keeps producing deformed pitchers. They don't have as much color, even though they get the same amount of light as the pitchers on the younger vines. A few of them grew normally, but some of them develop without a cap, a couple of them were deformed in size and shape and could never fully mature....they are just kind of....there. I can't fit bugs into the tiny hole in the top of these bulbous round things that are supposed to be pitchers. They do have nectar inside of them. I have a couple of other pitchers forming whos caps are too small, and so there is a small opening that happens while the pitcher is still immature.
Is this because I don't prune it? I love how it grows nice and tall, I prefer it that way. I also heard that if you let them grow tall, they will eventually flower.