Mr. Lumberjack.... (Got wood?)
My listening room contains around 15 or so artificial ficus trees. 5-footers. They are scattered around the room in what appears, but is decidedly NOT, random placement. They are VERY EFFECTIVE DIFFUSERS and "fixed" my room acoustics. A live tree would not work well in my basement room even though there are some large windows. But large live houseplants and potted trees might work and be a bit more aesthetically pleasing. Definitely high on the WAF.
I recommend leafy trees, real or artificial, to help room acoustics. I know of others, including a very high end electronics manufacturer, that use large plants and trees to help their room acoustics.