I went out and gathered a bunch of ivy, a few holly branches, and some wind-blown pine tufts, juniper and rosemary. I wrapped them around my windows. I hung heirloom ornaments and paper cranes. They look great.

If I wanted something more tree-like, I would wrap them around a tent-pole armature. If I lived where ivy turns brown in the winter, I'd stick to evergreens. Or maybe I'd try crochet.

No need to transport anything from anywhere, and no need for PVC.