Q.My hops have a rusty look
I had to move my hop plants, and the bed I’m using doesn’t have the best soil. I live in a location where soil is scarce, and the bed is mostly sphagnum moss. Could this be the reason that the hop leaves have a rusty kind of coloration along with the green? They seem otherwise healthy and are growing vigorously.

This is a rust fungus.
Air circulation can help inhibit it, but you will want to remove the leaves if possible.
Neem Oil can be used to treat it.
Here is a link that explains it.
https://www.gardeningknowhow.com/plant-problems/disease/learn-about-plant-rust-disease-and-rust-treatment.htm
https://www.gardeningknowhow.com/plant-problems/pests/pesticides/neem-oil-uses.htm