How to Make a Cat Climbing Tree Without Buying Any New Plastic Materials

Several months ago, blogger EcoCatLady left a comment on this blog about how she had avoided buying new plastic when her kitties needed a climbing tree by figuring out how to build one herself with all secondhand materials. She wrote:

My most recent success was that I wanted to get my kids (meaning kids of the feline variety) a scratching/climbing kitty tree for Christmas. I initially was going to buy one, and I found them online pretty cheap… but the more I researched, the more I discovered...