Hi there,
I live in a townhouse with a small fully paved courtyard out the back and am looking to make something to grow a variety of veggies in our backyard, I'm somewhat sure the attached image is AI generated but regardless its the closest thing to what I am looking to make as none of the off the shelf vertical garden options are really suitable for growing veggies, I wouldn't be making this as tall as the concept image either.

I'm interested to know what I should consider in building something like this which will be outdoors, what type of timber I should use and how I should protect it, I'd expect to paint it with some type of weather shield paint .etc
A mate mentioned I should use H3 treated timber, I haven't built anything before that's been permanently outdoors so just want to get some ideas, it would also be up against a colourbond fence, so whether it would need to be secured some way to prevent tipover, but it should be bottom heavy with this design.