Hi Hayley,
If you have a
permaculture garden, and you have a lot of woody material/ sources of manure, it is entirely possible that you already have mushrooms growing in your environment.
They also prefer growing under perennials.
If they occur naturally they will likely move over your site, depending on the state of your substrate. There are also different kinds of mushrooms that will occur throughout the seasons depending on the moisture of the soil, also primary, secondary and tertiary decomposers.
Fungi form mycelial networks in the soil that provide a food source for micro organisms ensuring healthy soil. They also release
water as a byproduct of reproduction- so you can think of them as a low maintenance irrigation system.
They will grow together with plants and like to live in the microclimate of the plant
canopy.
Plants put out exudates that are a food source of fungal hyphae in exchange for specific plant required nutrients - that the plant receives from the mycelial network, so they also move nutrients around in the soil based on the needs of plants.
I would suggest growing them under long lived annuals like capsicums that live about 5 years or shrub layers (perennials)
If you're planning to do them under annual, I'd probably suggest going with a primary decomposer. Maybe something in the coprinoid family.
It can take a few years fro mushrooms to fruit.
Its a game of patience and observation.
Also know that they will not pop up where you plant them. they're not like plants in that way. They will run in the soil until the are under threat to fruit and sporulate for continues existence.
Inoculating and planting logs may give you a more predictable crop.