For over 20 years I had some of the nicest Chamaedorea costa ricana in town. Then,they started being felled. To make a long story shorter..they were gone before I knew it and I had only seedlings that (thankfully) had fallen into pots here and there over the years. So, I did this with the last nice one in a pot...I got a large but flat piece of lava rock..like a slab. I threw some heavy garden dirt on it,and planted the palms. The whole shebang went into my small fish pond as an island supported by concrete blocks...FF some more...a couple of years ago I redid the pond,downsizing. I put the island and now 5-6' small clump on top of the ground by the back fence...mounding soil UP to it. And just kind of realized today I still have that palm doing well,and I still have gophers-ha. I sort of did my best just to hang on to the palms..and I also looked like I came up with a plan that could work for many small plants. As they get large- there is always a spot no gopher can eat into. I think.