I really like those posts! I'm going to need to build something similar very soon because I need branches heavier than the screen can support.
Is that a real log base? I was planning to use PT lumber post, maybe 4x4, for the stand and insert threaded sleeves into it pointing in various directions. Then I can put threaded rods in the branches so I can replace them as needed without damaging the main post.
The trunks are 6" PVC and the branches are wood crafting dowels secured with metal L-brackets and screwed into the trunks. The base of the trunk is the kind of plastic louvered drain you can pick up in Lowe's for a few bucks; the 6" pipe fits right in. The whole assembly was coated with a semi-rigid epoxy that's meant for this kind of thing; it's non toxic, self-extinguishing, UV resistant, feels a lot like tree bark, and should last pretty much forever. I used silicone putty to make a mold of the bark from a real tree I liked and used that to stamp the texture into the plastic while it was still soft. Finally, I used non-toxic stains and sealer (a product called Kennel Seal, meant for pet enclosures) to finish them off.
The nice thing about the PVC pipe trunk and drain base is that the waste water drains directly down the pipe through the screen. It also keeps the weight down. It took 2.5 gallons of the epoxy material to coat the trees, which by itself weighs quite a bit. These things are just over 4 feet high, so I imagine a real wood core would end up weighing far too much.
