Q. Why have you created the (Revit) assets on the planting category, and not, say Entourage?
For actual plants (trees) it makes sense for the scaling-hack-trick of the planting category template (this would be better served by being an instance parameter mind) - but we are never going to scale-size a person or a chair... and whilst we could introduce filters to differentiate (and exclude) the content from our model(s) proper*, the choice is somewhat strange - and in ways problematic.
*we model all viz. content on a non-primary design option to limit model & view-space bloat but that's beside the point.