Selecting Mushroom Spawn

What is mushroom spawn?
Mushroom spawn is simply any substance that has been inoculated with the vegetative growth of a fungus, which is called mycelium.

Spawn transfers mycelium onto a substrate, or material in which mushrooms grow. Common substrates include straw, sawdust, hardwood chips, logs, and even paper and cardboard, and it's helpful to first determine the type of substrate you'll be using before selecting spawn type.

Plug Spawn
You’re determined to give this mushroom cultivation thing a try, but terms like inoculation, mycelium  and ‘spawn run’ remind you of that biology class you dropped. Your Uncle Dave loves shiitake mushrooms, and has an overgrown woodlot teeming with spindly white oak trees and a beefy Stihl chainsaw that looks ready to take on the entire State of Oregon. Plug spawn would be a great choice. They’re grown on hardwood dowel pins, and ideal for inoculating newly cut hardwood logs. Plug spawn are also easy to use – simply drill holes, tap in the plug, and seal with wax. They’re sold in small quantities – enough to inoculate just a few logs - and included in most mushroom cultivation starter kits. Plug spawn also easily colonizes other wood fiber substrates like wood chips, paper, and cardboard.

Grain Spawn
Look out old Old Bossy. Rye, millet, and wheat are now often used in making grain spawn, and one big advantage it has over other spawn types is that it contains readily available nutrients for growing mycelium. Grain spawn is used to create more grain spawn, or inoculate mushrooms on substrates like pasteurized straw and enriched sawdust. Some growers even use birdseed or popcorn kernels as grain spawn. They’re great for growing mushrooms, but also feeding hungry wildlife, and for this reason, grain spawn is better saved for indoor cultivation.

Peg Spawn
At first that shady nook behind the garage seemed so promising. But the blackberry patch fizzled like a faulty bottle rocket, and the herb garden just melted into mush. The space is too narrow to squeeze in a compost pile, but perfect for cultivating mushrooms in a bed of wood chips using peg spawn. They’re essentially larger versions of the hardwood dowels used for plug spawn, and ideal for planting in landscape borders, and other tight spaces.

Thimble Spawn
Peanut butter and jelly. Yin and Yang. Brad and Angelina.  Some things are perfect for each other, and thimble spawn combine the convenience of plug spawn with the rapid growth rate of sawdust spawn. They’re made by molding sawdust spawn together with wax into the shape of a plug with a self-sealing cap, which eliminates the need to seal them with wax.

Sawdust Spawn
Do you have the patience of a 6 year old, and the budget of a college student? Sawdust spawn might be the ticket. Sawdust spawn is made by inoculating sterilized sawdust with mycelium. It’s economical , and because of the small size of the particles, can quickly inoculate hardwood  logs, wood chip beds, enriched sawdust, cardboard, and outdoor beds of unpasteurized straw. But remember that sawdust alone does not contain enough nutrients for growing mycelium, and it must be enriched with bran or another nitrogen source for reliable yields.