Orchids grow in two different ways. One is monopodial. Phals phall into this catagory. As the new leaves grow up the lower ones die off. The plant will send out new roots in order to find a hold and support the new section of the plant. They will try to find a hold on a branch or in the pot media and if not become arial. If the lower section of the plant, now leafless, looks bad it can be cut off and the newer roots planted into the media.