Plug Spawn Pack – White Elm Mushroom, Pleurotus ostreatus – 500 plugs


Product Description


500 plug pack

What is mushroom plug spawn?

Mushroom plug spawn is spiral grooved hardwood dowels infused (inoculated) with a specific mushroom species, in this case elm oyster or shirotamogitake (Pleurotus ostreatus). The mushroom mycelium (the white, root-like network of cells) colonizes and penetrates the dowels as it consumes the lignins provided by the wood. These plugs are used to inoculate freshly cut hardwood logs, stumps, or rounds to create a fruiting mushroom colony that can produce mushrooms for many years! These colonies are commonly referred to as mushroom logs. After waiting approximately one year from inoculation, a well cared for log will produce mushrooms several times a year, for 3-5 years.

Elm oyster logs are fun to make, require little maintenance, and will reliably produce mushrooms for years. Inoculate your own prepared logs using our 5/16in x 1in spiral grooved colonized plug spawn. A pack of 500 plugs is sufficient spawn to successfully inoculate 12-24 mushroom logs.

Making elm oyster mushroom logs

Use only recently cut, disease free hardwood logs of approximately three feet in length and four to six inches in diameter… about as long and thick as your leg.  For those of us in North America, we find elm oyster mushrooms prefers common deciduous trees such as elms, beech and maples.

Use disease free wood with the bark intact.

Prepare plug spawn inoculation sites by drilling 5/16in x 1 1/2in holes in a spiral pattern starting at one end of the log working towards the other. Space each hole approximately 4-6 inches away from the last. Number of holes will vary, for most logs 20-30 is good.

Inoculate the log by hammering the colonized plugs into each hole. Using a small punch to sink the top of the plug 1/4in or so below the bark surface is recommended.

Seal the inoculation sites by dripping melted cheese wax onto each hole. Cheese wax is easy to work with and can be melted in a double boiler. We use a small 2.5 quart crock pot dedicated to this purpose. Wax can be dripped on with a brush, distributed with a large dropper, turkey baster, or easy to use 10cc B-D inoculation syringes. A markable metal write-on tag can be stapled or tacked to the end of the log for long term identification.

Caring for elm oyster mushroom logs

Place logs in a shaded area and keep moist, creating stacks, or leaning against each other for support is best. Many report success with partially burying elm oyster logs in loose soil, so while we tend to recommend avoiding direct contact with soil for other mushroom log colonies, elm oysters may in fact benefit from this arrangement. Frequent and normal rainfall should keep them moist, but the logs may require a watering during dry spells. If the logs receive no notable rain for two weeks we recommend soaking them overnight in a tub or bucket filled with water.

Logs inoculated in early Spring may produce mushrooms by Fall, but will typically take up to one year to mature. Once mature, shock logs into producing mushroom by soaking them overnight and covering with a tarp or blanket. Remove cover when small mushrooms begin budding, usually 3-5 days. This is best done in summer as elm oysters are a warm weather species.

Properly maintained logs will continue to produce mushrooms for many seasons!

More information

Elm oyster mushrooms are widely cultivated in Asian and Australia.  The cook fruiting bodies have a firm, slightly crunchy texture and a nutty flavor that hold up well in any recipe including soups and stews.   Elm oysters have been show to kill invading insects, making them a good addition to any garden.

For more information on growing from plug spawn check out the following titles from our Mushroom Bookstore:


Available in 100 plug packs.

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