How to Grow Reishi: Bags, Buried Blocks and Logs

Reishi (Ganoderma lucidum, also called lingzhi) is unusual among home-grown mushrooms. You don’t grow it for the frying pan: the fruit body is hard, woody and corky. People grow it for its looks and to dry for tea or tinctures. Reishi also gives the grower a choice that few other species offer. Depending on how much fresh air it gets, the same culture can produce the familiar shiny, kidney-shaped “shelf” or a cluster of branching, finger-like “antlers”.

This guide compares the three main ways to grow reishi: indoor sawdust bags, buried fruiting blocks, and inoculated logs. It also explains how to steer the shape of the fruit body and when to harvest. The figures come from an Oregon State University Extension guide, India’s Directorate of Mushroom Research, a USDA-funded farm field day, and peer-reviewed cultivation studies. Where the sources disagree, the differences are shown rather than smoothed over.

Reishi at a glance

	Indoor sawdust bags	Buried fruiting blocks	Logs
Where	Grow tent, room or greenhouse	Shaded garden bed or greenhouse soil	Greenhouse, forest floor or shady yard
Substrate	Hardwood sawdust plus bran	Pre-colonised sawdust blocks	Fresh oak, maple or other suitable hardwood
Time to colonise	About 3 to 4 weeks	Bought or made already colonised	9 to 18 months
First harvest	Roughly 1 to 4 months after inoculation, depending on the schedule	About 2.5 to 3 months after planting	After the long spawn run, then for years
Control over shape	High	Moderate	Low

If you want to know more about reishi’s history and the research on its uses before you start, read our reishi explainer. This article is only about growing it.

Method 1: Indoor sawdust bags

Most commercially grown reishi comes from sterilised sawdust bags. The European Forest Institute notes that controlled indoor growing gives higher yields than forest cultivation.

The substrate

The published recipes are similar to one another. Each is mostly hardwood sawdust with a smaller share of bran and a little gypsum or chalk.

Source	Recipe	Sterilisation
ICAR Directorate of Mushroom Research (India)	Broadleaf sawdust with 20% wheat bran, about 65% moisture, gypsum and chalk to adjust pH to 5.5	22 psi for 2 hours
Fang et al. 2026, Journal of Fungi	84% sawdust, 15% wheat bran, 1% gypsum, 60% moisture	121°C for 2 hours
SARE farm field day handout	2 lb hardwood pellets, 4 oz bran, 2 tbsp gypsum, 1,400 ml water	15 psi for 2 hours

The SARE recipe is the easiest to copy at home, because hardwood fuel pellets are cheap and break down into sawdust when soaked. Make sure they are plain hardwood, with no additives. Supplemented sawdust always needs full sterilisation in a pressure cooker or autoclave. Our guide to sterilisation versus pasteurisation explains why.

Inoculation and spawn run

Once the bags have cooled, inoculate them with grain or sawdust spawn. The Directorate of Mushroom Research uses spawn at 3% of the substrate’s dry weight. It runs the bags at 28°C in darkness until they are “white all over”, which takes about 25 days. In the Journal of Fungi study, the bags were fully colonised after 25 days at 25°C in darkness. The SARE handout incubates at 70°F (21°C) and lists a shorter spawn run of 10 to 14 days. So plan for roughly two to four weeks, depending on temperature and spawn rate.

Fruiting: a staged approach

The Directorate of Mushroom Research gives the most detailed fruiting schedule, changing the conditions as the mushroom develops:

Pinning: cut back the plastic to expose the top of the substrate. Hold the bags at 28°C, 95% relative humidity (RH), about 1,500 ppm CO₂ and 800 lux of light.
Cap formation: once the top of each pinhead flattens out, lower humidity to 80% and CO₂ to 1,000 ppm.
Maturation: when the cap margin turns yellow, drop the temperature to 25°C and humidity to 60%.
Next flush: after harvest, reset to the pinning conditions. The Directorate reports 2 to 3 flushes per crop, with one crop taking about four months.

The SARE handout uses a warmer, wetter, simpler schedule: 70 to 80°F (21 to 27°C) throughout, with 95 to 100% RH for spawn run and pinning, and 90 to 95% during fruiting. Its own figures for the length of the fruiting stage are inconsistent: one part says 5 to 8 days, while the growth-parameter table says 60 days. In practice, a reishi cap takes weeks rather than days to mature, so plan for the longer timescale.

Shelf or antler: how to steer the shape

Fresh air (strictly speaking, carbon dioxide) is the main lever. Oregon State Extension notes that red reishi can form either finger-like antlers or a shelf, depending on how much oxygen it gets.

You want	What to do	Why
A classic flat, shiny cap	Give plenty of fresh air once pins appear, and moderate light	Low CO₂ lets the cap expand sideways
Branching antlers	Keep the bags in still, stale air, for example in a closed tent, a bag left mostly sealed, or a dim room	High CO₂ promotes stem growth and stops caps from opening

The research supports this. A 2026 Journal of Fungi paper notes that at CO₂ levels of about 0.1 to 1% (1,000 to 10,000 ppm), reishi tends to form antler-shaped fruit bodies. It also cites earlier work in which 0.1% CO₂ promoted stem growth and held back cap expansion. A 2021 study from Hue University in Vietnam produced typical antler-type fruit bodies on sawdust under “airless” conditions, in both light and darkness. The best treatment produced antlers 33 cm long and 28.02 g of fruit body per bag.

Antlers are not a failure. Some growers and buyers prefer them. Just make the choice on purpose rather than by accident.

Several young reishi fruit bodies with red centres and pale white growing edges emerging from a decaying stump — Young reishi still growing: note the pale margins. Photo: Matthew Wilkinson via iNaturalist, CC0 1.0.

Method 2: Buried fruiting blocks

Oregon State University Extension’s reishi guide, written for small woodland owners, describes a middle path. You start with sterilised sawdust-and-bran blocks, about 5 pounds each, inoculated with grain spawn. Once colonised, the blocks are buried in a bed outdoors or in a greenhouse.

Colonisation: about 20 days to full colonisation, with antlers starting to form at around 28 days. The guide says blocks are ready to plant when the antlers are 1 to 3 inches long.
Bed preparation: mix the soil with sawdust to hold moisture, or with wood chips to help drainage. Plant the blocks deep enough that they won’t float if water pools.
Shelf formation: 75 to 90 days after planting, with a possible second flush over another 75 to 90 days if the season is long enough.
Shade: if you use a greenhouse, the guide recommends 70 to 75% shade cloth.

This method suits growers who want reishi outdoors without waiting a year or more for logs to colonise.

Method 3: Inoculated logs

Log culture is the slowest route, but each log produces for several years. The Oregon State guide’s method:

Choose the wood: healthy, fairly straight oak or maple, 2 to 4 feet long and 4 to 7 inches across. Fell it in autumn or winter after the leaves have browned or dropped.
Timing: wait at least two days after felling, and inoculate within 30 days.
Drill and plug: drill holes 1 inch deep with a 12 mm bit, starting 1 inch from the end of the log. Space rows 2 to 3 inches apart and holes 3 to 6 inches apart in a staggered diamond pattern. Fill the holes with sawdust spawn and seal them with food-grade wax.
Spawn run: keep the logs off the ground on clean pallets in a greenhouse. Water them briefly once or twice a day so they stay moist but not waterlogged. Colonisation takes 9 to 18 months.
Plant: once mycelium shows at the ends of the log, plant the logs in trenches and cover them with a couple of inches of soil.

The same guide gives a useful rule of thumb: a log fruits for roughly one year per inch of diameter. A 6-inch log could produce for about six years, but thicker logs take longer to colonise. Fruiting typically comes in two flushes a season, from about April to August in Oregon. The European Forest Institute adds that reishi can be grown on fresh stumps and trunks, including birch, spruce, oak and alder, and that moist sites have higher success rates.

If you’ve grown shiitake on logs, the drilling and waxing will feel familiar. Our article on growing maitake on buried logs covers another hardwood species that is grown partly buried.

When to harvest

Reishi tells you when it has finished growing. The main sign is the cap margin:

Still growing: the edge is white or pale yellow, as in the photo above.
Ready: Oregon State says to harvest when the margin changes from white to red. The Directorate of Mushroom Research waits until the cap is fully reddish brown and spores have settled on the upper surface.
How: twist or cut the fruit body at the base. The Directorate advises removing the base fully so that no stub is left behind.

Oregon State gives about three months from pinning to maturity on blocks and logs. Indoor bags under controlled conditions can be quicker for each flush.

Drying and storage

Reishi is almost always used dried. The Directorate of Mushroom Research recommends drying below 50°C in a cabinet dryer, and describes freeze drying as the best option. It reports that 1 kg of fresh reishi gives about 450 g dried. That is a much higher dry yield than soft mushrooms give, because reishi contains far less water. Oregon State describes the mushrooms as corky and tough, so slicing large fruit bodies before drying makes them easier to handle.

Yields: what to expect

Source	Reported yield
Directorate of Mushroom Research	25% biological efficiency, or 250 g fresh reishi per 1 kg dry substrate, across 2 to 3 flushes
Hue University antler study	28.02 g per bag in the best antler treatment
Oregon State log guide	No weight given; logs fruit for roughly one year per inch of diameter

These are research or professional figures. Home results vary widely with strain, substrate and how well you manage fresh air.

Common mistakes

Expecting it to grow like oyster: reishi likes warmer conditions than many popular species. Our temperature cheat sheet compares the ranges for different species.
Getting antlers by accident: if you wanted caps, increase fresh-air exchange as soon as pins appear.
Harvesting too early: wait for the white margin to colour up.
Ignoring where the wood or substrate came from: the European Forest Institute points out that mushrooms can accumulate heavy metals and other contaminants from their surroundings. Use clean wood and substrate, especially if you plan to make tea from your harvest.
Picking wild “reishi” instead: several Ganoderma species grow wild, and some are easy to confuse. Oregon State lists G. applanatum, G. tsugae and G. oregonense in Oregon forests alone. Growing from a named culture avoids that confusion. Never rely on a photo or a description to decide that something you found in the wild is safe to consume.

A final note on use: our site covers the research on reishi in separate articles. Growing your own does not change the evidence, and anyone who takes medication or has a health condition should talk to a clinician before using reishi products.

Sources and further reading

Featured image: reishi by Piermario Maculan via iNaturalist (CC0 1.0). Inline photo by Matthew Wilkinson via iNaturalist (CC0 1.0).

How to Grow Reishi: Sawdust Bags, Buried Blocks, and Logs

Reishi at a glance