I’ve made two of these. One I left bare treated pine, but this one I wanted to tart up a bit.
I made the wheels by using the two biggest hole saws I had. I made the hubs with a small one. Then I just drilled holes right through the hub and glued 6mm dowel in. When the glue had dried I cut the dowels to fit the rim and glued them to the rim with Selleys exterior PVA glue.
The planter box and frame I made with scraps. There’s a single wooden strip as a rear axle with the wheels simply screwed onto the ends. I made the handlebar and forks with other scrap stuff, running 5mm bolts through as an axle for the front wheel.
Then some painting: a Rust-Oleum primer and Rust-Oleum poppy red for the body and silver for the headlight, and a flat black water-based paint for the tyres. It only needs a bell.
It’s fairly small and is suitable for a succulent or maybe Lobelia or Osteospermum from the Bunnings nursery.