I'm not sure which project you are referring to, but, I thought this one done with paint sticks might be helpful:
No doubt there are loads of planter ideas on Hometalk. Try the search bar at the top left, I'm sure you'll find what it is you're seeking.
Hello, I am not sure what you are searching for, but here is an easy build planter plan for you to try,
Lots of ideas here
Here is one I made that can be made from any thickness of wood. https://uniquecreationsbyanita.com/how-to-make-a-simple-planter-from-scrap-wood/