Shiitake mushroom growing: logs and sawdust blocks

Rich, meaty, and prized in kitchens worldwide, shiitake is one of the most rewarding mushrooms to grow yourself — and there are two very different ways to do it.

Shiitake mushroom growing is a bit of a patience game, but the payoff is a hardwood log or block that produces gourmet mushrooms for years. Shiitake is a wood-loving species, so unlike composting mushrooms it grows on dense hardwood — traditionally whole oak logs, or, for a faster harvest, supplemented hardwood sawdust blocks. The log method is the classic, low-tech, deeply satisfying route; the sawdust-block method trades a bit of that romance for speed. Below is how each one works, so you can pick the path that fits your patience and space. Shiitake, or Lentinula edodes, has been cultivated this way for centuries.

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The classic log method

Growing shiitake on logs is the time-honored approach. Start with fresh-cut hardwood logs — oak is best — about 3 to 6 inches across and 3 to 4 feet long, cut while the tree is dormant and used within a few weeks before wild fungi colonize them. Drill a grid of holes, pack in shiitake plug or sawdust spawn, and seal each hole with melted cheese wax to lock in moisture and keep contaminants out. That is the inoculation, and it is genuinely satisfying work. The same care about clean wood applies as with any grow; if you want the easiest possible start, our guide to the best beginner mushrooms covers faster species first.

Colonizing and fruiting the logs

After inoculation, the waiting begins. Stack the logs in a shady, humid spot and keep them from drying out while the mycelium slowly runs through the wood — this colonization takes anywhere from 6 to 18 months depending on wood, climate, and log size. Once a log is fully colonized, you force a flush by soaking it in cold water for 12 to 24 hours, which mimics a heavy rain and shocks the mycelium into fruiting; mushrooms usually push out within a week. After you harvest, let the log rest for a couple of months to recharge, then soak again — a good oak log will fruit like this for four to six years.

The faster sawdust-block method

If waiting a season or more sounds like too much, supplemented sawdust blocks are the quick route. These are bags of pasteurized or sterilized hardwood sawdust mixed with a nutrient supplement like wheat bran, inoculated with shiitake spawn. Because the substrate is rich and finely ground, the mycelium colonizes in weeks rather than months, and the block fruits in roughly two months total — often right on the counter indoors. The trade-off is that blocks need cleaner conditions to make and produce for a shorter time than logs, but for speed they are unbeatable, working much like the humidity setup in a fruiting chamber.

Harvest and enjoy

However you grow them, harvest shiitake when the caps have opened but the edges are still slightly curled under, twisting or cutting them from the wood. Fresh homegrown shiitake are richer and firmer than most store-bought, wonderful seared, in stir-fries, or in broth, and they also dry beautifully for long storage. If you end up with more than you can use right away, our guide on storing fresh mushrooms keeps them at their best, and the deeper cultivation background lives in our grow shiitake mushrooms guide.

Shiitake mushroom growing — FAQ

How do you grow shiitake mushrooms?

On hardwood logs inoculated with spawn and waxed, colonized 6 to 18 months then soaked to fruit — or on faster supplemented sawdust blocks.

What wood is best?

Fresh-cut oak is best; other dense hardwoods work too. Avoid softwoods and conifers, and inoculate logs within a few weeks of cutting.

How long does it take?

Logs take 6 to 18 months to colonize then fruit for years; sawdust blocks fruit in about two months.

How do you make logs fruit?

Soak a colonized log in cold water for 12 to 24 hours to shock it; mushrooms appear within a week, then rest and repeat.