All holders have a hole for a M3 wood screw. In the print files is an elevation for the wooden board.
Print settings:
Cactus:
https://www.ikea.com/de/de/p/cactaceae-pflanze-mit-uebertopf-kaktus-versch-arten-70402032/
Wood:
https://www.bauhaus.info/leimholzplatten/exclusivholz-leimholzplatte/p/14089216
The author marked this model as their own original creation.