Various species grow on hard or soft wood logs. If you have access to fresh logs, this is a great way of turning dead space into a garden. These will produce 1-3lbs of shiitake per log per year. I got them for free when a redditor was cutting down a tree on their farm so it can be very low-cost high-yield.
Yep, it's just colonisation time. Grain colonies take about a week, sawdust colonies about a month, logs take a year but fruit for up to five years.
Holy shit that's amazing that they keep going for years. Absolutely love shiitakes but I've only ever read how difficult they are to cultivate and never really looked into it.
If you have a good drill bit and unseasoned hardwood logs, it's very easy. Drill, insert the inoculated dowels from r/mycobazaar, cap the holes with bees wax, soak them for a day, and then you just stack them in the shade and water them every few weeks. 1-3lbs of shiitake per log per year.