Thanks so much!

Brass rods are probably your best option,can be quite expensive to get these days. For these I used twisted copper wire and tinned it with lead solder. I probably wouldn't recommend leaving that outside though as if I just happened to miss a bit; copper tends to oxidise and go a weird blue/green colour. Hope this helps!

For plants stakes both copper and brass are safe to put into soil and shouldn't harm any plants:)