Decided to pick up a broom mop wall mount holder for my leaf rakes. They have the same sized handle as your standard broom/mop, and the hooks on this one can be beneficial for hanging other things as well.
Sure it's not conventional with the marketing of the product, but it works just as well.
The holder attaches well enough with the double sided tape provided, but since this application is outdoors, I would strongly suggest screwing it in as well. It's going to be subject to humidity, cold, heat, maybe even a little water here and there (I have a lattice door on my lean too).